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Publication
Journal: Frontiers in Microbiology
February/23/2022
Abstract
Hypoxia environment has been widely used to promote exercise capacity. However, the underlying mechanisms still need to be further elucidated. In this study, mice were exposed to the normoxia environment (21% O2) or hypoxia environment (16.4% O2) for 4 weeks. Hypoxia-induced gut microbiota remodeling characterized by the increased abundance of Akkermansia and Bacteroidetes genera, and their related short-chain fatty acids (SCFAs) production. It was observed that hypoxia markedly improved endurance by significantly prolonging the exhaustive running time, promoting mitochondrial biogenesis, and ameliorating exercise fatigue biochemical parameters, including urea nitrogen, creatine kinase, and lactic acid, which were correlated with the concentrations of SCFAs. Additionally, the antibiotics experiment partially inhibited hypoxia-induced mitochondrial synthesis. The microbiota transplantation experiment demonstrated that the enhancement of endurance capacity induced by hypoxia was transferable, indicating that the beneficial effects of hypoxia on exercise performance were partly dependent on the gut microbiota. We further identified that acetate and butyrate, but not propionate, stimulated mitochondrial biogenesis and promoted endurance performance. Our results suggested that hypoxia exposure promoted endurance capacity partially by the increased production of SCFAs derived from gut microbiota remodeling.
Keywords: endurance performance; gut microbiota; hypoxia; mitochondrial biogenesis; short chain fatty acids.
Publication
Journal: Frontiers in Psychiatry
February/23/2022
Abstract
Background: Mental health problems after acute ischemic stroke (AIS) have caused wide public concerns, and the study on early identification of these disorders is still an open issue. This study aims to investigate the predictive effect of circulating neurofilament light (NfL) on long-term mental health status of AIS patients.
Methods: This study collected demographic information and mental health measurements from 304 AIS patients from May 1, 2016 to Dec 31, 2019. Baseline serum neurofilament light (NfL) was determined within 2 h since patient admission. Six months after AIS onset, the degree of symptoms of depression, anxiety, and insomnia was assessed by the Chinese versions of the 9-item Patient Health Questionnaire (PHQ-9), the 7-item Generalized Anxiety Disorder scale (GAD-7), the 7-item Insomnia Severity Index (ISI), respectively. Subjects were divided into the high NfL group and the low NfL group. Multivariate logistic regression analysis was performed to identify factors associated with these mental health problems.
Results: The high NfL group had significantly higher PHQ-9, GAD-7, and ISI scores than the low NfL group. The prediction of serum NfL for major depression generated a sensitivity of 70.27%, a specificity of 67.79% and an AUC of 0.694. The prediction of serum NfL for anxiety generated a sensitivity of 69.23%, a specificity of 64.02%, and an AUC of 0.683. The prediction of serum NfL for insomnia generated a sensitivity of 75.00%, a specificity of 66.43% and an AUC of 0.723. Higher serum NfL was a risk factor of post-AIS depression [ORs (95% CI): 4.427 (1.918, 10.217)], anxiety [ORs (95% CI): 3.063 (1.939, 6.692)], and insomnia [ORs (95% CI): 4.200 (1.526, 11.562)].
Conclusions: These findings imply that circulating NfL might be a potential biomarker of long-term mental health problems after AIS.
Keywords: anxiety; depression; insomnia; neurofilament light; post-stroke.
Publication
Journal: Frontiers in Aging Neuroscience
February/23/2022
Abstract
Sleep problems are increasingly present in the general population at any age, and they are frequently concurrent with-or predictive of-memory disturbances, anxiety, and depression. In this exploratory cross-sectional study, 54 healthy participants recruited in Naples (Italy; 23 females; mean age = 37.1 years, range = 20-68) completed the Pittsburgh Sleep Quality Index (PSQI) and a neurocognitive assessment concerning both verbal and visuospatial working memory as well as subjective measures of anxiety and depression. Then, 3T fMRI images with structural and resting-state functional sequences were acquired. A whole-brain seed-to-seed functional connectivity (FC) analysis was conducted by contrasting good (PSQI score <5) vs. bad (PSQI score ≥5) sleepers. Results highlighted FC differences in limbic and fronto-temporo-parietal brain areas. Also, bad sleepers showed an anxious/depressive behavioural phenotype and performed worse than good sleepers at visuospatial working-memory tasks. These findings may help to reveal the effects of sleep quality on daily-life cognitive functioning and further elucidate pathophysiological mechanisms of sleep disorders.
Keywords: anxiety; depression; functional connectivity; subjective sleep quality; working memory.
Publication
Journal: Nature
February/23/2022
Abstract
The Cretaceous-Palaeogene mass extinction around 66 million years ago was triggered by the Chicxulub asteroid impact on the present-day Yucatán Peninsula1,2. This event caused the highly selective extinction that eliminated about 76% of species3,4, including all non-avian dinosaurs, pterosaurs, ammonites, rudists and most marine reptiles. The timing of the impact and its aftermath have been studied mainly on millennial timescales, leaving the season of the impact unconstrained. Here, by studying fishes that died on the day the Mesozoic era ended, we demonstrate that the impact that caused the Cretaceous-Palaeogene mass extinction took place during boreal spring. Osteohistology together with stable isotope records of exceptionally preserved perichondral and dermal bones in acipenseriform fishes from the Tanis impact-induced seiche deposits5 reveal annual cyclicity across the final years of the Cretaceous period. Annual life cycles, including seasonal timing and duration of reproduction, feeding, hibernation and aestivation, vary strongly across latest Cretaceous biotic clades. We postulate that the timing of the Chicxulub impact in boreal spring and austral autumn was a major influence on selective biotic survival across the Cretaceous-Palaeogene boundary.
Publication
Journal: Journal of Human Reproductive Sciences
February/23/2022
Abstract
Background: Limited information is available on the aetiology and semen profiles of male infertility in Indian population.
Aim: The aim of this study is to study the clinical and semen characteristics of men attending the infertility clinic and also to understand the impact of World Health Organization (WHO) 2010 reference values on the diagnosis of male infertility.
Setting and design: A retrospective study evaluating the medical case records (January 2005 to December 2015, [n = 1906]) of men attending infertility clinic in Mumbai, India.
Materials and methods: The aetiology was classified based on the andrology evaluation and other investigations. Semen profiles were compared during the years 2005-2010 and 2011-2015 using WHO 1999 and WHO 2010 criteria, respectively.
Statistical analysis: The Chi-square and Mann-Whitney U tests were performed using Open Source Epidemiological software and Social science calculators.
Results: The aetiology of male infertility was determined in 62% of the men; while the cause remained undetermined in 38%. Varicocele (25%), urogenital infections (10%), sexual dysfunctions (8%) and vas aplasia (8%) were identified as major aetiologies in our cohort. Men with sexual dysfunctions and vas aplasia were significantly higher during the years 2011-2015 as compared to 2005-2010. Men having normozoospermia (10%) and azoospermia (3%) were increased, whereas those having oligoasthenozoospermia (17%) were reduced in 2011-2015 as compared to 2005-2010. According to WHO 1999 criteria , 12-15% of men showed abnormal semen profiles. The semen parameters of these men became normal on using WHO 2010 reference values.
Conclusions: Varicocele is the most common aetiology in infertile men. Idiopathic infertility was seen in a higher proportion among the infertile men.
Keywords: Aetiology of male infertility; World Health Organization reference value; semen; sperm; varicocele.
Publication
Journal: Cell Death and Differentiation
February/23/2022
Abstract
Hierarchical organization of intestine relies on the self-renewal and tightly regulated differentiation of intestinal stem cells (ISCs). Although signals like Wnt are known to sustain the continued intestinal renewal by maintaining ISCs activity and lineage commitment, molecular mechanisms underlying ISCs 'stemness' and supportive niche have not been well understood. Here, we found that CUL4B-RING ubiquitin ligase (CRL4B) regulates intestinal homeostasis by targeting immunity-related GTPase family M member 1 (IRGM1) for proteasomal degradation. CUL4B was mainly expressed at ISCs zone. Deletion of Cul4b led to reduced self-renewal of ISCs and a decreased lineage differentiation towards secretory progenitors through downregulated Wnt signals. Besides, Cul4b-null mice exhibited impaired Paneth cells number and structure. Mechanistically, CRL4B complex were associated with WD40 proteins and targeted IRGM1 at K270 for ubiquitination and proteosomal degradation. Impaired intestinal function caused by CUL4B deletion was rescued by down-regulation of its substrate IRGM1. Our results identified CUL4B as a novel regulator of ISCs and revealed a new 26 S proteasome degradation mechanism in intestine self-renewal and lineage commitment.
Publication
Journal: Nature Reviews Molecular Cell Biology
February/23/2022
Authors
Publication
Journal: Cell Death and Differentiation
February/23/2022
Abstract
Stratification of the epidermis is essential for the barrier function of the skin. However, the molecular mechanisms governing epidermal stratification are not fully understood. Herein, we demonstrate that enkurin domain-containing protein 1 (ENKD1) contributes to epidermal stratification by modulating the cell-division orientation of basal keratinocytes. The epidermis of Enkd1 knockout mice is thinner than that of wild-type mice due to reduced generation of suprabasal cells from basal keratinocytes through asymmetric division. Depletion of ENKD1 impairs proper orientation of the mitotic spindle and delays mitotic progression in cultured cells. Mechanistic investigation further reveals that ENKD1 is a novel microtubule-binding protein that promotes the stability of astral microtubules. Introduction of the microtubule-binding domain of ENKD1 can largely rescue the spindle orientation defects in ENKD1-depleted cells. These findings establish ENKD1 as a critical regulator of astral microtubule stability and spindle orientation that stimulates epidermal stratification in mammalian cells.
Publication
Journal: Nature Reviews Immunology
February/23/2022
Related with
Publication
Journal: Nature
February/23/2022
Abstract
Keywords: Ethics; Neuroscience; Policy.
Publication
Journal: Nature Communications
February/23/2022
Abstract
Deep learning has an increasing impact to assist research, allowing, for example, the discovery of novel materials. Until now, however, these artificial intelligence techniques have fallen short of discovering the full differential equation of an experimental physical system. Here we show that a dynamical neural network, trained on a minimal amount of data, can predict the behavior of spintronic devices with high accuracy and an extremely efficient simulation time, compared to the micromagnetic simulations that are usually employed to model them. For this purpose, we re-frame the formalism of Neural Ordinary Differential Equations to the constraints of spintronics: few measured outputs, multiple inputs and internal parameters. We demonstrate with Neural Ordinary Differential Equations an acceleration factor over 200 compared to micromagnetic simulations for a complex problem - the simulation of a reservoir computer made of magnetic skyrmions (20 minutes compared to three days). In a second realization, we show that we can predict the noisy response of experimental spintronic nano-oscillators to varying inputs after training Neural Ordinary Differential Equations on five milliseconds of their measured response to a different set of inputs. Neural Ordinary Differential Equations can therefore constitute a disruptive tool for developing spintronic applications in complement to micromagnetic simulations, which are time-consuming and cannot fit experiments when noise or imperfections are present. Our approach can also be generalized to other electronic devices involving dynamics.
Related with
Publication
Journal: Endocrine Journal
February/23/2022
Abstract
Numerous studies have examined the role of autophagy in thyroid cancer treatment; however there are discrepancies among the reported data, with some showing the pro-survival and others the anti-survival effects of autophagy. These discrepant results appear to be at least in part due to insufficient analyses or data misinterpretation as well as improper assessments of autophagic activity. Therefore, the present study re-evaluated the regulation of autophagic activity by various anticancer modalities and examined the role of autophagy in thyroid cancer treatment in three thyroid cancer cell lines (TPC1, ACT1 and KTC1). The immunofluorescence and DalGreen findings demonstrated that cisplatin, irradiation and sorafenib were all autophagy inducers as previously reported, but, unlike previous studies using thyroid cancer cells, doxorubicin acted as an inhibitor. KTC1 cells are unique because they only responded to cisplatin. The efficacy of anticancer therapeutics was significantly higher in chloroquine or 3-methyladenine-treated autophagy-defective cells than in autophagy-competent cells, thereby indicating the pro-survival effect of autophagy induced by anticancer therapeutics, which is partly due to inhibition of apoptosis. Thus, the present findings relating to several anticancer therapeutics and three thyroid cancer cell lines demonstrate the pro-survival effect of autophagy in thyroid cancer treatment. Although the present study only involved cell lines, it provides evidence for the beneficial combination of the anticancer therapeutic modalities with autophagy inhibitors, and proposes that autophagy inhibitors may serve as a possible adjunctive therapy for thyroid cancer.
Keywords: Anticancer therapeutics; Autophagy; Radiation; Thyroid.
Publication
Journal: Yakugaku Zasshi
February/23/2022
Abstract
Biosimilars are less expensive than their originators, and Japanese government policies call for their development and promotion. However, the adoption and prescription of some biosimilars, especially antibody/its-related ones, have been delayed for use in Japan, possibly due to concerns on the differences in quality attributes such as glycan structures between the originators and their biosimilars, and that clinical efficacy/safety studies are conducted for usually one disease and its results extrapolated to other indications. We conducted a questionnaire survey among physicians in four disease areas (hematology, medical oncology, rheumatoid arthritis, and inflammatory bowel disease), where biosimilars of antibody/its-related drugs have been approved, regarding their thoughts on the adoption and prescription of biosimilars in Japan from January to April 2020. We received totally 1,024 responses. When adopting biosimilars and explaining them to patients, physicians requested specific information including the comparative results of phase III clinical trials and quality characteristics between biosimilars and their originators; the results of clinical studies on switching from originators to their biosimilars; and a comparison of the estimated cost on patients in consideration of the high medical cost payment system. Priority differed depending on the studied disease areas. In terms of post-marketing information, physicians requested a variety of information. When explaining biosimilars to the patients, physicians would like to use general material from government describing the comparability between originators and their biosimilars. These results suggest that physicians sought more comparative information on the quality, efficacy, and patients' cost between originators and their biosimilars when adopting or prescribing biosimilars.
Keywords: adoption; antibody therapeutics; biosimilar; questionnaire survey.
Related with
Publication
Journal: BioScience Trends
February/23/2022
Abstract
In 2017, the World Health Organization highlighted polypharmacy as one of the key focus areas of the Global Patient Safety Challenge on Medication Safety. According to the experience of developed countries, the provision of primary pharmaceutical care plays a very important role in the intervention of polypharmacy in the elderly. It is necessary to assess the associations between elderly polypharmacy status and primary care in developing countries. The findings of this paper provide the prevalence of polypharmacy in patients with comorbid hypertension, and the factors associated with it. A total of 19,332 elderly patients with hypertension were completed, among which the mean (SD) number of diseases was 4.83 (1.99), the mean (SD) daily maximum number of drugs was 5.13 (2.89), and the rate of polypharmacy was 50.5%. Age, living areas, total number of visits, preference for medical institutions and the number of diseases were associated with polypharmacy. Among them, advanced age, greater number of visits and diseases are the risk factors of polypharmacy for elderly patients with comorbid hypertension. The rate of polypharmacy in patients who intend to seek treatment in community healthcare centers is low. A total of 9,603 pharmaceutical workers worked in Shanghai public hospitals in 2020, among them 52.0% worked in the central city area, and more than 70% worked in secondary and tertiary hospitals. There was a large mismatch between patients' medical preference and the number of pharmaceutical personnel. As a consequence, it is necessary to strengthen the development of community pharmaceutical care in primary medical institutions for elderly polypharmacy management.
Keywords: comorbid hypertension; polypharmacy; primary pharmaceutical care; the elderly; visit preference.
Related with
Publication
Journal: BioScience Trends
February/23/2022
Abstract
Hepatocellular carcinoma (HCC) is the fifth most common malignancy and the second leading cause of cancer-related mortality worldwide. This review is an updated version that summarizes comprehensive guidelines published from January 2001 to January 2022 worldwide with a focus on the clinical management of HCC. The electronic databases MEDLINE, the Chinese SinoMed, and the Japanese CiNii were systematically searched. A total of 22 characteristic guidelines for HCC management were ultimately included, including 1 international guideline, 11 guidelines from Asia, 5 from Europe, 4 from the America, and 1 from Australia. If guidelines were published in multiple versions, the most recent update was included, and surveillance, diagnosis, and treatment were compared. The composition of and recommendations in current guidelines on HCC varied, so these guidelines were regrouped and diagnostic and treatment algorithms were summarized graphically to provide the latest information to clinicians. The diagnostic criteria were grouped into 2 categories: a "Size-based pathway" and a "Non-size-based pathway". The treatment criteria were summarized according to different treatment algorithms, and mainstream treatment options were reviewed. Findings from comparison of current guidelines might help target and concentrate efforts to improve the clinical management of HCC. However, further studies are needed to improve the management and outcomes of HCC. More straightforward or refined guidelines would help guide doctors to make better decisions in the treatment of HCC in the future.
Keywords: clinical guideline; diagnosis; hepatocellular carcinoma; surveillance; treatment.
Related with
Publication
Journal: BioScience Trends
February/23/2022
Abstract
As the number of people with COVID-19 increases daily around the world, point-of-care testing (POCT) is gaining attention as a tool that can provide immediate test results and greatly help to deter infection and determine what to do next. POCT has several drawbacks such as a low sensitivity and specificity, but according to studies POCT has increased sensitivity on par with that of polymerase chain reaction testing. The advantage of POCT is that the results can be obtained quickly, regardless of the location. To further enhance its benefits, POCT is being developed and researched in conjunction with the Internet of medical things (IoMT), which allows POCT results to be collected, recorded, and managed over a network. IoMT will be beneficial not only for the use of POCT simply as a testing tool but also for its integration into diagnostic and health management systems. IoMT will enable people to regularly receive their test results in their daily lives and to provide personalized diagnosis and treatment of individual conditions, which will be beneficial in terms of disease prevention and maintenance of health.
Keywords: COVID-19; Internet of medical things; Japan; point-of-care testing.
Publication
Journal: Journal of Veterinary Medical Science
February/23/2022
Abstract
This study aimed to evaluate the clinical utility of ultrasonography in the diagnosis of a newborn calf presenting with extended swelling within its right flank, in addition to its therapeutic planning. Ultrasonograms of the bilateral flanks identified thinning of the external and internal oblique abdominal muscles in whole areas of the abdominal walls. A right lateral abdominal hernia associated with thin abdominal muscular structures was diagnosed ultrasonographically. The right flank abdominal hernia was successfully reconstructed through a modified Mayo mattress suture. This allowed the overlapping of the two very thin structures of the abdominal walls, resulting in the creation of a thicker structure of the right lateral abdominal walls. Reconstruction of the abdominal walls using this method could prevent re-protrusion of the viscera during calf growth.
Keywords: Mayo mattress suture; calf; lateral abdominal hernia; thin abdominal muscle; ultrasonography.
Publication
Journal: Current Opinion in Allergy and Clinical Immunology
February/23/2022
Publication
Journal: Obesity
February/23/2022
Publication
Journal: Gut
February/23/2022
Abstract
Objective: We previously reported a characterisation of the hepatocellular carcinoma (HCC) immune contexture and described an immune-specific class. We now aim to further delineate the immunogenomic classification of HCC to incorporate features that explain responses/resistance to immunotherapy.
Design: We performed RNA and whole-exome sequencing, T-cell receptor (TCR)-sequencing, multiplex immunofluorescence and immunohistochemistry in a novel cohort of 240 HCC patients and validated our results in other cohorts comprising 660 patients.
Results: Our integrative analysis led to define: (1) the inflamed class of HCC (37%), which includes the previously reported immune subclass (22%) and a new immune-like subclass (15%) with high interferon signalling, cytolytic activity, expression of immune-effector cytokines and a more diverse T-cell repertoire. A 20-gene signature was able to capture ~90% of these tumours and is associated with response to immunotherapy. Proteins identified in liquid biopsies recapitulated the inflamed class with an area under the ROC curve (AUC) of 0.91; (2) The intermediate class, enriched in TP53 mutations (49% vs 29%, p=0.035), and chromosomal losses involving immune-related genes and; (3) the excluded class, enriched in CTNNB1 mutations (93% vs 27%, p<0.001) and PTK2 overexpression due to gene amplification and promoter hypomethylation. CTNNB1 mutations outside the excluded class led to weak activation of the Wnt-βcatenin pathway or occurred in HCCs dominated by high interferon signalling and type I antigen presenting genes.
Conclusion: We have characterised the immunogenomic contexture of HCC and defined inflamed and non-inflamed tumours. Two distinct CTNNB1 patterns associated with a differential role in immune evasion are described. These features may help predict immune response in HCC.
Keywords: hepatocellular carcinoma; immune response; immunotherapy; liver immunology; molecular oncology.
Publication
Journal: Journal of Neuroscience
February/23/2022
Abstract
Mossy cells (MCs) of the dentate gyrus (DG) are key components of an excitatory associative circuit established by reciprocal connections with dentate granule cells (GCs). MCs are implicated in place field encoding, pattern separation and novelty detection, as well as in brain disorders such as temporal lobe epilepsy and depression. Despite their functional relevance, little is known about the determinants that control MC activity. Here, we examined whether MCs express functional kainate receptors (KARs), a subtype of glutamate receptors involved in neuronal development, synaptic transmission, and epilepsy. Using mouse hippocampal slices, we found that bath application of submicromolar and micromolar concentrations of the KAR agonist kainic acid induced inward currents and robust MC firing. These effects were abolished in GluK2 KO mice, indicating the presence of functional GluK2-containing KARs in MCs. In contrast to CA3 pyramidal cells, which are structurally and functionally similar to MCs and express synaptic KARs at mossy fiber (MF) inputs (i.e., GC axons), we found no evidence for KAR-mediated transmission at MF-MC synapses, indicating that most KARs at MCs are extrasynaptic. Immunofluorescence and immunoelectron microscopy analyses confirmed the extrasynaptic localization of GluK2-containing KARs in MCs. Finally, blocking glutamate transporters, a manipulation that increases extracellular levels of endogenous glutamate, was sufficient to induce KAR-mediated inward currents in MCs, suggesting that MC-KARs can be activated by increases in ambient glutamate. Our findings provide the first direct evidence of functional extrasynaptic KARs at a critical excitatory neuron of the hippocampus.SIGNIFICANCE STATEMENTHilar mossy cells (MCs) are an understudied population of hippocampal neurons that form an excitatory loop with dentate granule cells. MCs have been implicated in pattern separation, spatial navigation, and epilepsy. Despite their importance in hippocampal function and disease, little is known about how MC activity is recruited. Here, we show for the first time that MCs express extrasynaptic kainate receptors (KARs), a subtype of glutamate receptors critically involved in neuronal function and epilepsy. While we found no evidence for synaptic KARs in MCs, KAR activation induced strong action potential firing of MCs, raising the possibility that extracellular KARs regulate MC excitability in vivo and may also promote dentate gyrus hyperexcitability and epileptogenesis.
Publication
Journal: Journal of Neuroscience
February/23/2022
Abstract
Working memory ability continues to mature into adulthood in humans and non-human primates. At the single neuron level, adolescent development is characterized by increased prefrontal firing rate in the delay period, but less is known about how coordinated activity between neurons is altered. Local field potentials (LFP) provide a window into the computations carried out by the local network. To address the effects of adolescent development on LFP activity, three male rhesus monkeys were trained to perform an oculomotor delayed response task and tested at both the adolescent and adult stage. Simultaneous single-unit and LFP signals were recorded from areas 8a and 46 of the dorsolateral prefrontal cortex. In both the cue and delay period, power relative to baseline increased in the gamma frequency range (32 - 128 Hz). The changes between developmental stages could not be accounted for by differences in performance and were observed in more posterior as well as more anterior recording sites. In the adult stage, high-firing neurons were also more likely to reside at sites with strong gamma power increase from baseline. For both stages, the gamma power increase in the delay was selective for sites with neuron encoding stimulus information in their spiking. Gamma power and neuronal firing did not show stronger temporal correlations. Our results establish gamma power decrease to be a feature of prefrontal cortical maturation.SIGNIFICANCE STATEMENTGamma-frequency oscillations in extracellular field recordings (such as LFP or EEG) are a marker of normal interactions between excitatory and inhibitory neurons in neural circuits. Abnormally low gamma power during working memory is seen in conditions such as schizophrenia. We sought to examine whether the immature prefrontal cortex similarly exhibits lower power in the gamma frequency range during working memory, in a non-human primate model of adolescence. Contrary to this expectation, the adolescent PFC exhibited stronger gamma power during the maintenance of working memory. Our findings reveal an unknown developmental maturation trajectory of gamma band oscillations, propose a refinement of information encoding during PFC maturation, and raise the possibility that schizophrenia represent an excessive state of prefrontal maturation.
Publication
Journal: Journal of Pharmacology and Experimental Therapeutics
February/23/2022
Abstract
12-lipoxigenase (12-LOX) is implicated in regulation of platelet activation processes and can be a new promising target for antiplatelet therapy. However, investigations of 12-LOX were restricted by the lack of specific and potent 12-LOX inhibitors and by controversial data concerning the 12-LOX metabolites role in platelet functions. A novel specific 12-LOX inhibitor ML355 was shown to inhibit platelet aggregation without adverse side effects on hemostasis, however, the molecular mechanisms of its action on platelets are poorly understood. Here, we showed that ML355 inhibited platelet activation induced by thrombin or thromboxane A2, but not by collagen-related peptide (Crp-XL). ML355 blocked Akt, PI3K and Erk1/2, but not p38, Syk or PLCγ2 phosphorylation in activated platelets. The main inhibitory effect of low doses ML355 (1-20 µM) on thrombin activated platelets was mediated by the decrease in reactive oxygen species level whereas high dose of ML355 (50 µM) caused cyclic adenosine monophosphate (cAMP) activation. ML355 did not affect the activity of NO-dependent soluble guanylyl cyclase, nor did it affect relaxation of preconstricted aortic rings in mice. ML355 itself did not affect platelet viability, but at 50 µM doses blocked caspase-dependent apoptosis induced by Bcl-2 inhibitor ABT-737. Significance Statement Current paper provides novel and original data concerning molecular mechanisms of 12-LOX inhibitor ML355 action on platelets. These data reveal antiplatelet and protective effects of ML355 on platelets and may be of importance for both antiplatelet and anticancer therapy.
Keywords: Apoptosis; Platelets; cAMP; cGMP; lipoxygenases; reactive oxygen species.
Publication
Journal: Genome Research
February/23/2022
Abstract
The morphology of breast cancer cells is often used as an indicator of tumor severity and prognosis. Additionally, morphology can be used to identify more fine-grained, molecular developments within a cancer cell, such as transcriptomic changes and signalling pathway activity. Delineating the interface between morphology and signalling is important to understand the mechanical cues that a cell processes in order to undergo epithelial-to-mesenchymal transition and consequently metastasize. However, the exact regulatory systems that define these changes remain poorly characterized. In this study, we employ a network-systems approach to integrate imaging data and RNA-seq expression data. Our workflow allows the discovery of unbiased and context-specific gene expression signatures and cell signalling sub-networks relevant to the regulation of cell shape, rather than focusing on the identification of previously known, but not always representative, pathways. By constructing a cell-shape signalling network from shape-correlated gene expression modules and their upstream regulators, we found central roles for developmental pathways such as WNT and Notch as well as evidence for the fine control of NF-kB signalling by numerous kinase and transcriptional regulators. Further analysis of our network implicates a gene expression module enriched in the RAP1 signalling pathway as a mediator between the sensing of mechanical stimuli and regulation of NF-kB activity, with specific relevance to cell shape in breast cancer.
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