SenNet recommendations for detecting senescent cells in different tissues.

Once considered a tissue culture-specific phenomenon, cellular senescence has now been linked to various biological processes with both beneficial and detrimental roles in humans, rodents and other species. Much of our understanding of senescent cell biology still originates from tissue culture studies, where each cell in the culture is driven to an irreversible cell cycle arrest. By contrast, in tissues, these cells are relatively rare and difficult to characterize, and it is now established that fully differentiated, postmitotic cells can also acquire a senescence phenotype. The SenNet Biomarkers Working Group was formed to provide recommendations for the use of cellular senescence markers to identify and characterize senescent cells in tissues. Here, we provide recommendations for detecting senescent cells in different tissues based on a comprehensive analysis of existing literature reporting senescence markers in 14 tissues in mice and humans. We discuss some of the recent advances in detecting and characterizing cellular senescence, including molecular senescence signatures and morphological features, and the use of circulating markers. We aim for this work to be a valuable resource for both seasoned investigators in senescence-related studies and newcomers to the field.

The transcription factor LRF promotes integrin ß7 expression by and gut homing of CD8αα+ intraepithelial lymphocyte precursors.

While T cell receptor (TCR) αß+CD8α+CD8ß- intraepithelial lymphocytes (CD8αα+ IELs) differentiate from thymic IEL precursors (IELps) and contribute to gut homeostasis, the transcriptional control of their development remains poorly understood. In the present study we showed that mouse thymocytes deficient for the transcription factor leukemia/lymphoma-related factor (LRF) failed to generate TCRαß+CD8αα+ IELs and their CD8ß-expressing counterparts, despite giving rise to thymus and spleen CD8αß+ T cells. LRF-deficient IELps failed to migrate to the intestine and to protect against T cell-induced colitis, and had impaired expression of the gut-homing integrin α4ß7. Single-cell RNA-sequencing found that LRF was necessary for the expression of genes characteristic of the most mature IELps, including Itgb7, encoding the ß7 subunit of α4ß7. Chromatin immunoprecipitation and gene-regulatory network analyses both defined Itgb7 as an LRF target. Our study identifies LRF as an essential transcriptional regulator of IELp maturation in the thymus and subsequent migration to the intestinal epithelium.

microRNA-449a reduces growth hormone-stimulated senescent cell burden through PI3K-mTOR signaling.

Cellular senescence, a hallmark of aging, has been implicated in the pathogenesis of many major age-related disorders, including neurodegeneration, atherosclerosis, and metabolic disease. Therefore, investigating novel methods to reduce or delay the accumulation of senescent cells during aging may attenuate age-related pathologies. microRNA-449a-5p (miR-449a) is a small, noncoding RNA down-regulated with age in normal mice but maintained in long-living growth hormone (GH)-deficient Ames Dwarf (df/df) mice. We found increased fibroadipogenic precursor cells, adipose-derived stem cells, and miR-449a levels in visceral adipose tissue of long-living df/df mice. Gene target analysis and our functional study with miR-449a-5p have revealed its potential as a serotherapeutic. Here, we test the hypothesis that miR-449a reduces cellular senescence by targeting senescence-associated genes induced in response to strong mitogenic signals and other damaging stimuli. We demonstrated that GH downregulates miR-449a expression and accelerates senescence while miR-449a upregulation using mimetics reduces senescence, primarily through targeted reduction of p16Ink4a, p21Cip1, and the PI3K-mTOR signaling pathway. Our results demonstrate that miR-449a is important in modulating key signaling pathways that control cellular senescence and the progression of age-related pathologies.

NPS-2143 inhibit glioma progression by suppressing autophagy through mediating AKT-mTOR pathway.

Gliomas are the most common tumours in the central nervous system. In the present study, we aimed to find a promising anti-glioma compound and investigate the underlying molecular mechanism. Glioma cells were subjected to the 50 candidate compounds at a final concentration of 10 µM for 72 h, and CCK-8 was used to evaluate their cytotoxicity. NPS-2143, an antagonist of calcium-sensing receptor (CASR), was selected for further study due to its potent cytotoxicity to glioma cells. Our results showed that NPS-2143 could inhibit the proliferation of glioma cells and induce G1 phase cell cycle arrest. Meanwhile, NPS-2143 could induce glioma cell apoptosis by increasing the caspase-3/6/9 activity. NPS-2143 impaired the immigration and invasion ability of glioma cells by regulating the epithelial-mesenchymal transition process. Mechanically, NPS-2143 could inhibit autophagy by mediating the AKT-mTOR pathway. Bioinformatic analysis showed that the prognosis of glioma patients with low expression of CASR mRNA was better than those with high expression of CASR mRNA. Gene set enrichment analysis showed that CASR was associated with cell adhesion molecules and lysosomes in glioma. The nude mice xenograft model showed NPS-2143 could suppress glioma growth in vivo. In conclusion, NPS-2143 can suppress the glioma progression by inhibiting autophagy.

Isotropic Quantum Griffiths Singularity in Nd_{0.8}Sr_{0.2}NiO_{2} Infinite-Layer Superconducting Thin Films.

This work reports on the emergence of quantum Griffiths singularity (QGS) associated with the magnetic field induced superconductor-metal transition (SMT) in unconventional Nd_{0.8}Sr_{0.2}NiO_{2} infinite layer superconducting thin films. The system manifests isotropic SMT features under both in-plane and perpendicular magnetic fields. Importantly, after scaling analysis of the isothermal magnetoresistance curves, the obtained effective dynamic critical exponents demonstrate divergent behavior when approaching the zero-temperature critical point B_{c}^{*}, identifying the QGS characteristics. Moreover, the quantum fluctuation associated with the QGS can quantitatively explain the upturn of the upper critical field around zero temperature for both the in-plane and perpendicular magnetic fields in the phase boundary of SMT. These properties indicate that the QGS in the Nd_{0.8}Sr_{0.2}NiO_{2} superconducting thin film is isotropic. Moreover, a higher magnetic field gives rise to a metallic state with the resistance-temperature relation R(T) exhibiting lnT dependence among the 2-10 K range and T^{2} dependence of resistance below 1.5 K, which is significant evidence of Kondo scattering. The interplay between isotropic QGS and Kondo scattering in the unconventional Nd_{0.8}Sr_{0.2}NiO_{2} superconductor can illustrate the important role of rare region in QGS and help to uncover the exotic superconductivity mechanism in this system.

Photomediated One-Pot Three-Component Approach Enables the Formal Direct N-Acylation/Sulfonylation and α-C-H Functionalization of 1,2,3,4-Tetrahydroisoquinoline.

N-Acyl/sulfonyl-α-functionalized 1,2,3,4-tetrahydroisoquinolines (THIQs) are significant structural motifs in organic synthesis and drug discovery. However, the one-pot approach enabling direct difunctionalization of THIQs remains challenging. Herein we report a photomediated one-pot three-component strategy to access N-acyl/sulfonyl-α-functionalized THIQs. This method features the use of oxygen (from air) as the green oxidant, high atom and step economy, and decent structural diversity. The synthetic applicability of the method was further demonstrated via the facile construction of valuable bioactive molecules. Mechanistic studies indicated that oxidation with singlet oxygen and the acceptor-less dehydrogenation were involved in the photoredox process.

A rotational/roto-translational constraint method for condensed matter.

Molecular rotations influence numerous condensed matter phenomena but are often difficult to isolate in molecular dynamics (MD) simulations. This work presents a rotational/roto-translational constraint algorithm designed for condensed matter simulations. The method is based on the velocity Verlet scheme, ensuring a direct constraint on velocity and simplifying implementation within material simulation software packages. We implemented the algorithm in a customized version of a CP2K package and validated its effectiveness through MD simulations of molecule and crystal. The results demonstrate successful selective constraint of rotational and roto-translational motions, enabling stable long-term simulations. This capability opens avenues for studying rotation-related phenomena (e.g., paddle-wheel mechanism in solid-state electrolytes) and constrained sampling.

Correction: Histone demethylase LSD1 restricts influenza A virus infection by erasing IFITM3-K88 monomethylation.

[This corrects the article DOI: 10.1371/journal.ppat.1006773.].

Genetic association between coffee/caffeine consumption and the risk of obstructive sleep apnea in the European population: a two-sample Mendelian randomization study.

BACKGROUND: The association between coffee/caffeine consumption and obstructive sleep apnea (OSA) risk remains unclear. PURPOSE: To determine the relationship between coffee/caffeine consumption and the risk of OSA, using the Mendelian randomization (MR) method in the European population. METHODS: Two sets of coffee consumption-associated genetic variants were, respectively, extracted from the recent genome-wide meta-analysis (GWMA) and genome-wide association study (GWAS) of coffee consumption. Taking other caffeine sources into account, genetic variants associated with caffeine consumption from tea and plasma caffeine (reflecting total caffeine intake) were also obtained. The inverse variance weighted (IVW) technique was utilized as the primary analysis, supplemented by the MR-Egger, weighted-median, and MR-Pleiotropy RESidual Sum and Outlier (PRESSO) techniques. Leave-one-out (LOO) analysis was performed to assess whether the overall casual estimates were driven by a single SNP. Additional sensitivity analyses were performed using similar methods, while the genetic variants associated with confounders, e.g., body mass index and hypertension, were excluded. RESULTS: The IVW method demonstrated that coffee consumption GWMA (OR: 1.065, 95% CI 0.927-1.224, p = 0.376), coffee consumption GWAS (OR: 1.665, 95% CI 0.932-2.977, p = 0.086), caffeine from tea (OR: 1.198, 95% CI 0.936-1.534, p = 0.151), and blood caffeine levels (OR: 1.054, 95% CI 0.902-1.231, p = 0.508) were unlikely to be associated with the risk of OSA. The other three methods presented similar results, where no significant associations were found. No single genetic variant was driving the overall estimates by the LOO analysis. These findings were also supported by the sensitivity analyses with no confounding genetic variants. CONCLUSION: Our study found no association between coffee/caffeine consumption and the risk of OSA.

Relationship between dietary carotenoid intake and sleep duration in American adults: a population-based study.

OBJECTIVE: To investigate the relationship between dietary carotenoid intake and sleep duration. METHODS: Adults enrolled in the National Health and Nutrition Examination Survey (NHANES) 2007-2018 without missing information on dietary carotenoid intake (α-carotene, ß-carotene, ß-cryptoxanthin, lycopene, and lutein + zeaxanthin), sleep duration, and covariates were included. Participants' carotenoid consumption was divided into three groups by quartiles and sleep duration was grouped as short (< 7 h/night), optimal (7-8 h/night), and long (> 8 h/night). Multinominal logistic regression was constructed to examine the association between dietary carotenoid intake and sleep duration. Restricted cubic spline (RCS) regression was further utilized to explore their dose-response relationship. The weighted quantile sum (WQS) model was adopted to calculate the mixed and individual effect of 5 carotenoid sub-types on sleep duration. RESULTS: Multinominal logistic regression presented that people with higher intakes of α-carotene, ß-carotene, ß-cryptoxanthin, lycopene, and lutein + zeaxanthin were less likely to sleep too short or too long. Consistent with the findings from multinominal logistic regression, the RCS models suggested a reverse U-shaped relationship between sleep duration and carotenoid intakes. The mixed effects were also significant, where ß-cryptoxanthin and lutein + zeaxanthin were the top 2 contributors associated with the decreased risks of short sleep duration, while ß-carotene, α-carotene, and ß-cryptoxanthin were the main factors related to the lower risk of long sleep duration. CONCLUSION: Our study revealed that the American adults with optimal sleep duration were associated with more dietary carotenoid intake, in comparison to short or long sleepers.

Comparison of remifentanil and esketamine in combination with propofol for patient sedation during fiberoptic bronchoscopy.

BACKGROUND: Ideal sedation and analgesia strategies for fiberoptic bronchoscopy have not been found. At present, propofol based sedation strategy still has some defects, such as respiratory depression and blood pressure drop. It is difficult to meet the requirements of safety and effectiveness at the same time. The aim of this study was to compare the clinical efficacy of propofol/remifentanil with propofol/esketamine for patient sedation during fiberoptic bronchoscopy. METHOD: Patients undergoing fiberoptic bronchoscopy were randomly assigned to propofol/ remifentanil (PR group; n = 42) or propofol/esketamine (PK group; n = 42) for sedation and analgesia. The primary outcome was the rate of transient hypoxia (oxygen saturation (SpO2) < 95%). The secondary outcomes are the intraoperative hemodynamics, including the changes in blood pressure, heart rate, the incidence of adverse reactions, the total amount of propofol usage were recorded, and the satisfaction level of patients and bronchoscopists. RESULTS: After sedation, the arterial pressure and heart rate of patients in the PK group were stable without significant decrease. Decreases in diastolic blood pressure, mean arterial pressure, and heart rate were observed in patients in the PR group (P < 0.05), although it was not of clinical relevance. The dosage of propofol in the PR group was significantly higher than that in the PK group (144 ± 38 mg vs. 125 ± 35 mg, P = 0.012). Patients in the PR group showed more transient hypoxia (SpO2 < 95%) during surgery (7 vs. 0, 0% versus 16.6%, P = 0.018), more intraoperative choking (28 vs. 7, P < 0.01), postoperative vomiting (22 vs. 13, P = 0.076) and vertigo (15 vs. 13, P = 0.003). Bronchoscopists in the PK group showed more satisfaction. CONCLUSION: Compared with remifentanil, the combination of esketamine with propofol in fiberoptic bronchoscopy leaded to more stable intraoperative hemodynamics, lower dosage of propofol, lower transient hypoxia rate, fewer incidence of adverse events, and greater bronchoscopists satisfaction.

The ubiquitin ligase Stub1 negatively modulates regulatory T cell suppressive activity by promoting degradation of the transcription factor Foxp3.

Regulatory T (Treg) cells suppress inflammatory immune responses and autoimmunity caused by self-reactive T cells. The key Treg cell transcription factor Foxp3 is downregulated during inflammation to allow for the acquisition of effector T cell-like functions. Here, we demonstrate that stress signals elicited by proinflammatory cytokines and lipopolysaccharides lead to the degradation of Foxp3 through the action of the E3 ubiquitin ligase Stub1. Stub1 interacted with Foxp3 to promote its K48-linked polyubiquitination in an Hsp70-dependent manner. Knockdown of endogenous Stub1 or Hsp70 prevented Foxp3 degradation. Furthermore, the overexpression of Stub1 in Treg cells abrogated their ability to suppress inflammatory immune responses in vitro and in vivo and conferred a T-helper-1-cell-like phenotype. Our results demonstrate the critical role of the stress-activated Stub1-Hsp70 complex in promoting Treg cell inactivation, thus providing a potential therapeutic target for the intervention against autoimmune disease, infection, and cancer.

Aster-C coordinates with COP I vesicles to regulate lysosomal trafficking and activation of mTORC1.

Nutrient sensing by the mTOR complex 1 (mTORC1) requires its translocation to the lysosomal membrane. Upon amino acids removal, mTORC1 becomes cytosolic and inactive, yet its precise subcellular localization and the mechanism of inhibition remain elusive. Here, we identified Aster-C as a negative regulator of mTORC1 signaling. Aster-C earmarked a special rough ER subdomain where it sequestered mTOR together with the GATOR2 complex to prevent mTORC1 activation during nutrient starvation. Amino acids stimulated rapid disassociation of mTORC1 from Aster-C concurrently with assembly of COP I vesicles which escorted mTORC1 to the lysosomal membrane. Consequently, ablation of Aster-C led to spontaneous activation of mTORC1 and dissociation of TSC2 from lysosomes, whereas inhibition of COP I vesicle biogenesis or actin dynamics prevented mTORC1 activation. Together, these findings identified Aster-C as a missing link between lysosomal trafficking and mTORC1 activation by revealing an unexpected role of COP I vesicles in mTORC1 signaling.

The deubiquitinase USP44 promotes Treg function during inflammation by preventing FOXP3 degradation.

The transcription factor forkhead box P3 (FOXP3) is essential for the development of regulatory T cells (Tregs) and their function in immune homeostasis. Previous studies have shown that in natural Tregs (nTregs), FOXP3 can be regulated by polyubiquitination and deubiquitination. However, the molecular players active in this pathway, especially those modulating FOXP3 by deubiquitination in the distinct induced Treg (iTreg) lineage, remain unclear. Here, we identify the ubiquitin-specific peptidase 44 (USP44) as a novel deubiquitinase for FOXP3. USP44 interacts with and stabilizes FOXP3 by removing K48-linked ubiquitin modifications. Notably, TGF-ß induces USP44 expression during iTreg differentiation. USP44 co-operates with USP7 to stabilize and deubiquitinate FOXP3. Tregs genetically lacking USP44 are less effective than their wild-type counterparts, both in vitro and in multiple in vivo models of inflammatory disease and cancer. These findings suggest that USP44 plays an important role in the post-translational regulation of Treg function and is thus a potential therapeutic target for tolerance-breaking anti-cancer immunotherapy.

Multi-layered g-C3N4 as a Fluorescent Probe for Hg2+ Detection.

Hg2+ is one of the most toxic heavy metal ions that exist in the environment and it forms large numbers of toxic binary compounds. Accurate and rapid detection of the concentration of heavy metal ions is a prerequisite technology to achieve pollution control and prevention. Fluorescent probes have attracted extensive attention because of their high sensitivity, prominent precision, convenient and fast visualization of heavy metals. Herein, we report multi-layered graphitic carbon nitride via a simple thermopolymerization treatment as a very effectual fluorescent probe for sensitive and selective detection of Hg2+ with a limit of detection as low as 1.14 nM.

Cardiolipin remodeling by ALCAT1 links hypoxia to coronary artery disease by promoting mitochondrial dysfunction.

Cardiolipin is a mitochondrial signature phospholipid that plays a pivotal role in maintaining cardiac health. A loss of tetralinoleoyl cardiolipin (TLCL), the predominant cardiolipin species in the healthy mammalian heart, is implicated in the pathogenesis of coronary heart disease (CHD) through poorly defined mechanisms. Here, we identified acyl-coenzyme A:lysocardiolipin acyltransferase-1 (ALCAT1) as the missing link between hypoxia and CHD in an animal model of myocardial infarction (MI). ALCAT1 is an acyltransferase that promotes mitochondrial dysfunction in aging-related diseases by catalyzing pathological remodeling of cardiolipin. In support of a causative role of ALCAT1 in CHD, we showed that ALCAT1 expression was potently upregulated by MI, linking myocardial hypoxia to oxidative stress, TLCL depletion, and mitochondrial dysfunction. Accordingly, ablation of the ALCAT1 gene or pharmacological inhibition of the ALCAT1 enzyme by Dafaglitapin (Dafa), a potent and highly specific ALCAT1 inhibitor, not only restored TLCL levels but also mitochondrial respiration by attenuating signal transduction pathways mediated by hypoxia-inducible factor 1α (HIF-1α). Consequently, ablation or pharmacological inhibition of ALCAT1 by Dafa effectively mitigated CHD and its underlying pathogenesis, including dilated cardiomyopathy, left ventricle dysfunction, myocardial inflammation, fibrosis, and apoptosis. Together, the findings have provided the first proof-of-concept studies for targeting ALCAT1 as an effective treatment for CHD.

Extracellular Vesicles Isolated From Hypoxia-Preconditioned Adipose-Derived Stem Cells Promote Hypoxia-Inducible Factor 1α-Mediated Neovascularization of Random Skin Flap in Rats.

BACKGROUND: Random flaps are widely used for wound repair. However, flap necrosis is a serious complication leading to the failure of operation. Our previous study demonstrated a great proangiogenic potential of hypoxia-treated adipose-derived stem cells-extracellular vesicles (HT-ASC-EVs). Thus, we aim to evaluate the effect of HT-ASC-EVs in the survival and angiogenesis of random skin flap in rats. METHODS: Adipose-derived stem cells-extracellular vesicles were respectively isolated from adipose-derived stem cell culture medium of 3 donors via ultracentrifugation. The expression of hypoxia-inducible factor 1α (HIF-1α) and proangiogenic potential of HT-ASC-EVs and ASC-EVs were compared by co-culturing with human umbilical vein endothelial cells. Forty male Sprague-Dawley rats were randomly divided into 3 group (n = 10/group). A 9 × 3-cm random skin flap was separated from the underlying fascia with both sacral arteries sectioned on each rat. The survival and angiogenesis of flaps treated by ASC-EVs or HT-ASC-EVs were also compared. Laser Doppler flowmetry and immunohistochemistry were used to evaluate skin perfusion and angiogenesis of skin flaps on postoperative day 7. RESULTS: Hypoxia-treated adipose-derived stem cells-extracellular vesicles further improve the proliferation, migration, tube formation with upregulated HIF-1α, and VEGF expression of human umbilical vein endothelial cells in vitro, compared with ASC-EVs. In vivo, postoperatively injecting HT-ASC-EVs suppressed necrosis rate (29.1 ± 2.8% vs 59.2 ± 2.1%) and promoted the angiogenesis of skin flap including improved skin perfusion (803.2 ± 24.3 vs 556.3 ± 26.7 perfusion unit), increased number of CD31-positive cells, and upregulated expression of HIF-1α in vascular endothelium on postoperative day 7, compared with ASC-EVs. CONCLUSIONS: Intradermal injecting HT-ASC-EVs improve the survival of random skin flap by promoting HIF-1α-mediated angiogenesis in rat model.

Comparison of biological and mechanical properties of different paranasal sinus mucosa in goat.

OBJECTIVE: The present study was designed to explore endurable pressure intensity of different paranasal sinus mucosa in goats. METHOD: Mucosa commonly involved in maxillary sinus augmentation, including mucosa from maxillary sinus crest, maxillary sinus floor, and frontal sinus, were harvested in a computed tomography-guided manner. The obtained mucosa was then sectioned into square and irregular ones for maximum endurable pressure intensity determination and morphological observation, respectively. RESULTS: Thickness of paranasal sinus mucosa, as determined under morphological staining by an optical microscope with a graduated eyepiece, were calculated. And the results showed that the average thickness of maxillary sinus crest mucosa, floor mucosa, and frontal sinus mucosa in goats were 410.03 ± 65.97 µm, 461.33 ± 91.37 µm and 216.90 ± 46.47 µm, respectively. Significant differences between maxillary sinus crest and frontal sinus, maxillary sinus floor, and frontal sinus were observed (P < 0.05). Maximum endurable pressure intensity was determined by utilizing a self-made clamp device and the results revealed maximum endurable pressure intensity of maxillary sinus crest mucosa, floor mucosa and frontal sinus mucosa in goats were 260.08 ± 80.12Kpa, 306.90 ± 94.37Kpa and 121.72 ± 31.72Kpa, respectively. Also, a statistically significant difference was observed when comparing the endurable pressure intensity between maxillary sinus crest and frontal sinus, maxillary sinus floor, and frontal sinus (P < 0.05). Further correlation analysis also revealed a positive correlation between the thickness of mucosa of the maxillary sinus and frontal sinus and maximum endurable pressure intensity (P < 0.05). CONCLUSION: Mucosal thickness and maximum endurable pressure intensity of maxillary sinus crest and floor were larger than that of frontal sinus mucosa and a positive correlation between the thickness of mucosa and endurable pressure intensity was observed. Our results thus might provide an experimental basis and guidance for mucosa-related problems involved maxillary sinus augmentation.

Correction: Histone demethylase LSD1 restricts influenza A virus infection by erasing IFITM3-K88 monomethylation.

[This corrects the article DOI: 10.1371/journal.ppat.1006773.].

Histone demethylase LSD1 restricts influenza A virus infection by erasing IFITM3-K88 monomethylation.

The histone demethylase LSD1 has been known as a key transcriptional coactivator for DNA viruses such as herpes virus. Inhibition of LSD1 was found to block viral genome transcription and lytic replication of DNA viruses. However, RNA virus genomes do not rely on chromatin structure and histone association, and the role of demethylase activity of LSD1 in RNA virus infections is not anticipated. Here, we identify that, contrary to its role in enhancing DNA virus replication, LSD1 limits RNA virus replication by demethylating and activating IFITM3 which is a host restriction factor for many RNA viruses. We have found that LSD1 is recruited to demethylate IFITM3 at position K88 under IFNα treatment. However, infection by either Vesicular Stomatitis Virus (VSV) or Influenza A Virus (IAV) triggers methylation of IFITM3 by promoting its disassociation from LSD1. Accordingly, inhibition of the enzymatic activity of LSD1 by Trans-2-phenylcyclopropylamine hydrochloride (TCP) increases IFITM3 monomethylation which leads to more severe disease outcomes in IAV-infected mice. In summary, our findings highlight the opposite role of LSD1 in fighting RNA viruses comparing to DNA viruses infection. Our data suggest that the demethylation of IFITM3 by LSD1 is beneficial for the host to fight against RNA virus infection.