Acute hormone secretion triggered by G protein-coupled receptor (GPCR) activation underlies many fundamental physiological processes. GPCR signalling is negatively regulated by β-arrestins, adaptor ...molecules that also activate different intracellular signalling pathways. Here we reveal that TRV120027, a β-arrestin-1-biased agonist of the angiotensin II receptor type 1 (AT1R), stimulates acute catecholamine secretion through coupling with the transient receptor potential cation channel subfamily C 3 (TRPC3). We show that TRV120027 promotes the recruitment of TRPC3 or phosphoinositide-specific phospholipase C (PLCγ) to the AT1R-β-arrestin-1 signalling complex. Replacing the C-terminal region of β-arrestin-1 with its counterpart on β-arrestin-2 or using a specific TAT-P1 peptide to block the interaction between β-arrestin-1 and PLCγ abolishes TRV120027-induced TRPC3 activation. Taken together, our results show that the GPCR-arrestin complex initiates non-desensitized signalling at the plasma membrane by coupling with ion channels. This fast communication pathway might be a common mechanism of several cellular processes.
ABSTRACT
Endoreduplication is prevalent during plant growth and development, and is often correlated with large cell and organ size. Despite its prevalence, the transcriptional regulatory mechanisms ...underlying the transition from mitotic cell division to endoreduplication remain elusive. Here, we characterize ETHYLENE‐RESPONSIVE ELEMENT BINDING FACTOR 4 (ERF4) as a positive regulator of endoreduplication through its function as a transcriptional repressor. ERF4 was specifically expressed in mature tissues in which the cells were undergoing expansion, but was rarely expressed in young organs. Plants overexpressing ERF4 exhibited much larger cells and organs, while plants that lacked functional ERF4 displayed smaller organs than the wild‐type. ERF4 was further shown to regulate cell size by controlling the endopolyploidy level in the nuclei. Moreover, ERF4 physically associates with the class I TEOSINTE BRANCHED 1/CYCLOIDEA/PCF (TCP) protein TCP15, a transcription factor that inhibits endoreduplication by activating the expression of a key cell‐cycle gene, CYCLIN A2;3 (CYCA2;3). A molecular and genetic analysis revealed that ERF4 promotes endoreduplication by directly suppressing the expression of CYCA2;3. Together, this study demonstrates that ERF4 and TCP15 function as a module to antagonistically regulate each other's activity in regulating downstream genes, thereby controlling the switch from the mitotic cell cycle to endoreduplication during leaf development. These findings expand our understanding of how the control of the cell cycle is fine‐tuned by an ERF4–TCP15 transcriptional complex.
The ETHYLENE‐RESPONSIVE ELEMENT BINDING FACTOR 4 and TEOSINTE BRANCHED 1/CYCLOIDEA/PCF15 transcription factors interact and antagonistically regulate the expression of the key cell‐cycle gene CYCA2;3, hence controlling cell cycle progression during leaf development in Arabidopsis.
Oral cancer is one of the most common cancers worldwide, and there are currently no biomarkers approved for aiding its management. Although many potential oral cancer biomarkers have been discovered, ...very few have been verified in body fluid specimens in parallel to evaluate their clinical utility. The lack of appropriate multiplexed assays for chosen targets represents one of the bottlenecks to achieving this goal. In the present study, we develop a peptide immunoaffinity enrichment-coupled multiple reaction monitoring-mass spectrometry (SISCAPA-MRM) assay for verifying multiple reported oral cancer biomarkers in saliva. We successfully produced 363 clones of mouse anti-peptide monoclonal antibodies (mAbs) against 36 of 49 selected targets, and characterized useful mAbs against 24 targets in terms of their binding affinity for peptide antigens and immuno-capture ability. Comparative analyses revealed that an equilibrium dissociation constant (KD) cut-off value < 2.82 × 10−9m could identify most clones with an immuno-capture recovery rate >5%. Using these mAbs, we assembled a 24-plex SISCAPA-MRM assay and optimized assay conditions in a 25-μg saliva matrix background. This multiplexed assay showed reasonable precision (median coefficient of variation, 7.16 to 32.09%), with lower limits of quantitation (LLOQ) of <10, 10–50, and >50 ng/ml for 14, 7 and 3 targets, respectively. When applied to a model saliva sample pooled from oral cancer patients, this assay could detect 19 targets at higher salivary levels than their LLOQs. Finally, we demonstrated the utility of this assay for quantification of multiple targets in individual saliva samples (20 healthy donors and 21 oral cancer patients), showing that levels of six targets were significantly altered in cancer compared with the control group. We propose that this assay could be used in future studies to compare the clinical utility of multiple oral cancer biomarker candidates in a large cohort of saliva samples.
In materials chiral fermions such as Weyl fermions are characterized by nonzero chiral charges, which are singular points of Berry curvature in momentum space. Recently, new types of chiral fermions ...beyond Weyl fermions have been discovered in structurally chiral crystals CoSi, RhSi and PtAl. Here, we have synthesized RhSn single crystals, which have opposite structural chirality to the CoSi crystals we previously studied. Using angle-resolved photoemission spectroscopy, we show that the bulk electronic structures of RhSn are consistent with the band calculations and observe evident surface Fermi arcs and helical surface bands, confirming the existence of chiral fermions in RhSn. It is noteworthy that the helical surface bands of the RhSn and CoSi crystals have opposite handedness, meaning that the chiral fermions are reversed in the crystals of opposite structural chirality. Our discovery establishes a direct connection between chiral fermions in momentum space and chiral lattices in real space.
We have demonstrated that the hydroxyl radicals (OH•) and hydrogen gas can be generated by the application of mechanical force to the active edge sites of the MoS2 nanoflowers in a dark environment. ...The non-centrosymmetric structure of the single- and few-layered MoS2 nanoflowers were uniformly dispensed in the aqueous solution. A mechanical force was applied to the aqueous solution, and the hydroxyl radicals were generated from the MoS2 nanoflowers because a piezoelectric spontaneous polarization was created around the single- and odd number of layers. To exclude the dye adsorption effect during the decomposition process, the MoS2 nanoflowers with 99.9 wt% were removed from the solution by the centrifuged process to obtain the solution without the nanoflowers. Interestingly, the solution can decompose the organic dye (i.e. Rhodamine B) instantly (see the video recording in the Supporting Information). Based on the fluorescence (FL) spectra, the solution contained with the highly oxidized free radicals, which was strongly dependent on the concentration of the MoS2 nanoflowers in the aqueous solution. The formation of the M- (VMo′′′′) and S-vacancies (VS••) sites on the single-layer MoS2 acted as the F-center defects, leading to the hydroxyl radicals being accommodated on the sites to decompose the organic dye molecules and prolong the radical's lifetime up to 6 h. More importantly, with applying the ultrasonic vibration to the MoS2 nanoflowers in the deionized water and ethanol solution, a remarkable hydrogen peak was observed by the gas chromatography mass spectrometry. Moreover, as increasing the concentration of the MoS2 nanoflowers in the solution, the intensity of the hydrogen generation was increased. This is the first work to demonstrate that the dye molecule can be instantly decomposed by the free radicals solution and produced the hydrogen gas using the piezoelectricity of the MoS2 nanoflowers with the application of mechanical force in a dark environment.
Direct watering splitting was contributed from the MoS2 nanoflowers by piezo-catalytic effect. The transparent radical solution as prepared from the MoS2 nanoflowers can instantly decompose the organic dyes. Display omitted
•Direct watering splitting was contributed from the MoS2 nanoflowers by piezocatalytic effect.•Transparent radical solution as prepared from the MoS2 nanoflowers can instantly decompose the organic dyes.•The F-center defects bonds the hydroxyl radicals to prolong their lifetime up to 6 h.
There exist differences in the epidemiological characteristics, clinicopathological features, tumor biological characteristics, treatment patterns, and drug selections between gastric cancer patients ...from the Eastern and Western countries. The Chinese Society of Clinical Oncology (CSCO) has organized a panel of senior experts specializing in all sub‐specialties of gastric cancer to compile a clinical guideline for the diagnosis and treatment of gastric cancer since 2016 and renews it annually. Taking into account regional differences, giving full consideration to the accessibility of diagnosis and treatment resources, these experts have conducted expert consensus judgment on relevant evidence and made various grades of recommendations for the clinical diagnosis and treatment of gastric cancer to reflect the value of cancer treatment and meeting health economic indexes in China. The 2021 CSCO Clinical Practice Guidelines for Gastric Cancer covers the diagnosis, treatment, follow‐up, and screening of gastric cancer. Based on the 2020 version of the CSCO Chinese Gastric Cancer guidelines, this updated guideline integrates the results of major clinical studies from China and overseas for the past year, focused on the inclusion of research data from the Chinese population for more personalized and clinically relevant recommendations. For the comprehensive treatment of non‐metastatic gastric cancer, attentions were paid to neoadjuvant treatment. The value of perioperative chemotherapy is gradually becoming clearer and its recommendation level has been updated. For the comprehensive treatment of metastatic gastric cancer, recommendations for immunotherapy were included, and immune checkpoint inhibitors from third‐line to the first‐line of treatment for different patient groups with detailed notes are provided.
The Chinese Society of Clinical Oncology (CSCO) organized a panel of senior experts specializing in all sub‐specialties of gastric cancer to compile the clinical guideline for gastric cancer in 2016 and then renewed it every year. The 2021 CSCO Clinical Practice Guidelines for gastric cancer covered the diagnosis, treatment, follow‐up and screening.
The inflammasome adaptor protein, ASC, contributes to both innate immune responses and inflammatory diseases via self-oligomerization, which leads to the activation of the protease, caspase-1. Here, ...we report that the cytosolic tyrosine kinases, FAK and Pyk2, are differentially involved in NLRP3 and AIM2 inflammasome activation. The inhibition of FAK and Pyk2 with RNA interference or chemical inhibitors dramatically abolished ASC oligomerization, caspase-1 activation, and IL-1β secretion in response to NLRP3 or AIM2 stimulation. Pyk2 is phosphorylated by the kinase Syk and relocalizes to the ASC specks upon NLRP3 inflammasome activation. Pyk2, but not FAK, could directly phosphorylate ASC at Tyr146, and only the phosphorylated ASC could participate in speck formation and trigger IL-1β secretion. Moreover, the clinical-trial-tested Pyk2/FAK dual inhibitor PF-562271 reduced monosodium urate-mediated peritonitis, a disease model used for studying the consequences of NLRP3 activation. Our results suggest that although Pyk2 and FAK are involved in inflammasome activation, only Pyk2 directly phosphorylates ASC and brings ASC into an oligomerization-competent state by allowing Tyr146 phosphorylation to participate ASC speck formation and subsequent NLRP3 inflammation.
Saliva is an attractive sample source for the biomarker-based testing of several diseases, especially oral cancer. Here, we sought to apply multiplexed LC-MRM-MS to precisely quantify 90 ...disease-related proteins and assess their intra- and interindividual variability in saliva samples from healthy donors.
We developed two multiplexed LC-MRM-MS assays for 122 surrogate peptides representing a set of disease-related proteins. Saliva samples were collected from 10 healthy volunteers at three different time points (Day 1 morning and afternoon, and Day 2 morning). Each sample was spiked with a constant amount of a
N-labeled protein and analyzed by MRM-MS in triplicate. Quantitative results from LC-MRM-MS were calculated by single-point quantification with reference to a known amount of internal standard (heavy peptide).
The CVs for assay reproducibility and technical variation were 13 and 11%, respectively. The average concentrations of the 99 successfully quantified proteins ranged from 0.28 ± 0.58 ng mL
for profilin-2 (PFN2) to 8.55 ±8.96 μg mL
for calprotectin (S100A8). For the 90 proteins detectable in >50% of samples, the average CVs for intraday, interday, intraindividual, and interindividual samples were 38%, 43%, 45%, and 69%, respectively. The fluctuations of most target proteins in individual subjects were found to be within ± twofold.
Our study elucidated the intra- and interindividual variability of 90 disease-related proteins in saliva samples from healthy donors. The findings may facilitate the further development of salivary biomarkers for oral and systemic diseases.
Inhaled particulate matter 2.5 (PM
) can cause lung injury by inducing serious inflammation in lung tissue. Renin-angiotensin system (RAS) is involved in the pathogenesis of inflammatory lung ...diseases and regulates inflammatory response. Angiotensin-converting enzyme II (ACE2), which is produced through the angiotensin-converting enzyme (ACE)/angiotensin II (Ang II) axis, protects against lung disease. However, few studies have focused on the relationships between PM
and ACE2. Therefore, we aimed to explore the role of ACE2 in PM
-induced acute lung injury (ALI). An animal model of PM
-induced ALI was established with wild type (C57BL/6, WT) and ACE2 gene knockout (ACE2 KO) mice. The mice were exposed to PM
through intratracheal instillation once a day for 3 days (6.25 mg/kg/day) and then sacrificed at 2 days and 5 days after PM
instillation. The results show that resting respiratory rate (RRR), levels of inflammatory cytokines, ACE and MMPs in the lungs of WT and ACE2 KO mice were significantly increased at 2 days postinstillation. At 5 days postinstillation, the PM
-induced ALI significantly recovered in the WT mice, but only partially recovered in the ACE2 KO mice. The results hint that PM
could induce severe ALI through pulmonary inflammation, and the repair after acute PM
postinstillation could be attenuated in the absence of ACE2. Additionally, our results show that PM
-induced ALI is associated with signaling p-ERK1/2 and p-STAT3 pathways and ACE2 knockdown could increase pulmonary p-STAT3 and p-ERK1/2 levels in the PM
-induced ALI.
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