The positive feedback loop of the NAT10/Mybbp1a/p53 axis promotes cardiomyocyte ferroptosis to exacerbate cardiac I/R injury

Ferroptosis is a nonapoptotic form of regulated cell death that has been reported to play a central role in cardiac ischemia‒reperfusion (I/R) injury. N-acetyltransferase 10 (NAT10) contributes to cardiomyocyte apoptosis by functioning as an RNA ac4c acetyltransferase, but its role in cardiomyocyte ferroptosis during I/R injury has not been determined. This study aimed to elucidate the role of NAT10 in cardiac ferroptosis as well as the underlying mechanism. The mRNA and protein levels of NAT10 were increased in mouse hearts after I/R and in cardiomyocytes that were exposed to hypoxia/reoxygenation. P53 acted as an endogenous activator of NAT10 during I/R in a transcription-dependent manner. Cardiac overexpression of NAT10 caused cardiomyocyte ferroptosis to exacerbate I/R injury, while cardiomyocyte-specific knockout of NAT10 or pharmacological inhibition of NAT10 with Remodelin had the opposite effects. The inhibition of cardiomyocyte ferroptosis by Fer-1 exerted superior cardioprotective effects against the NAT10-induced exacerbation of post-I/R cardiac damage than the inhibition of apoptosis by emricasan. Mechanistically, NAT10 induced the ac4C modification of Mybbp1a, increasing its stability, which in turn activated p53 and subsequently repressed the transcription of the anti-ferroptotic gene SLC7A11. Moreover, knockdown of Mybbp1a partially abolished the detrimental effects of NAT10 overexpression on cardiomyocyte ferroptosis and cardiac I/R injury. Collectively, our study revealed that p53 and NAT10 interdependently cooperate to form a positive feedback loop that promotes cardiomyocyte ferroptosis to exacerbate cardiac I/R injury, suggesting that targeting the NAT10/Mybbp1a/p53 axis may be a novel approach for treating cardiac I/R.

Mettl13 protects against cardiac contractile dysfunction by negatively regulating C-Cbl-mediated ubiquitination of SERCA2a in ischemic heart failure

Ischemic heart failure (HF) remains a leading cause of morbidity and mortality. Maintaining homeostasis of cardiac function and preventing cardiac remodeling deterioration are critical to halting HF progression. Methyltransferase-like protein 13 (Mettl13) has been shown to regulate protein translation efficiency by acting as a protein lysine methyltransferase, but its role in cardiac pathology remains unexplored. This study aims to characterize the roles and mechanisms of Mettl13 in cardiac contractile function and HF. We found that Mettl13 was downregulated in the failing hearts of mice post-myocardial infarction (MI) and in a cellular model of oxidative stress. Cardiomyocyte-specific overexpression of Mettl13 mediated by AAV9-Mettl13 attenuated cardiac contractile dysfunction and fibrosis in response to MI, while silencing of Mettl13 impaired cardiac function in normal mice. Moreover, Mettl13 overexpression abrogated the reduction in cell shortening, Ca2+ transient amplitude and SERCA2a protein levels in the cardiomyocytes of adult mice with MI. Conversely, knockdown of Mettl13 impaired the contractility of cardiomyocytes, and decreased Ca2+ transient amplitude and SERCA2a protein expression in vivo and in vitro. Mechanistically, Mettl13 impaired the stability of c-Cbl by inducing lysine methylation of c-Cbl, which in turn inhibited ubiquitination-dependent degradation of SERCA2a. Furthermore, the inhibitory effects of knocking down Mettl13 on SERCA2a protein expression and Ca2+ transients were partially rescued by silencing c-Cbl in H2O2-treated cardiomyocytes. In conclusion, our study uncovers a novel mechanism that involves the Mettl13/c-Cbl/SERCA2a axis in regulating cardiac contractile function and remodeling, and identifies Mettl13 as a novel therapeutic target for ischemic HF.

Tropical parasitic itch in returned travellers and immigrants from endemic areas

Itch is the most common skin symptom among tropical parasitic diseases (TPD), but there are limited data about its characteristics in these conditions. In dermatology practices and travellers' health clinics in the developed world, itch is a common complaint among travellers returning from endemic areas, as well among migrants arriving from endemic areas, where they may have been exposed to TPD. Studying aspects of pruritus among TPD may lead to improvements in prompt, accurate diagnosis and management of these conditions. This review examines the major itch-inducing TPDs, including schistosomiasis, echinococcosis, onchocerciasis, scabies, cutaneous larva migrans, larva currens, African trypanosomiasis, dracunculiasis and other causes of travel associated pruritus. We focus on the link between pruritus and other symptoms, aetiology, clinical staging and therapeutic options for these parasitic illnesses. Because some tropical parasitic diseases can present with significant pruritus, we attempt to identify aspects of the pruritus that are characteristic of-or unique to-specific conditions. These diagnostic insights may help clinicians create a rational and focused differential diagnosis and help determine optimal disease management pathways. In this sense, management involves treating the individual, seeking epidemiologically linked cases, preventing recurrences or relapses, and reducing spread of the disease.

Scalp dysesthesia: a neuropathic phenomenon

Scalp dysesthesia is an abnormal sensation of the scalp in the absence of cutaneous disease. It is characterized by a burning and/or itching sensation and can be related to a variety of neurogenic or psychogenic causes. This condition is extremely bothersome and is also common- especially amongst the geriatric population, in women, in patients with diabetes mellitus and patients with psychiatric history. However, despite its prevalence in many populations, there is limited data about its causes and characteristics. Given its limited cutaneous manifestations it is also easily misdiagnosed and an underrecognized cause of scalp pruritus in the dermatological community. Therefore, education on scalp dysesthesia is paramount to helping physicians identify and provide appropriate treatment for these patients. This review focuses predominately on the neurogenic causes (with a brief review of psychogenic itch) of scalp dysesthesia and the therapeutics that have been found to be effective for this condition. Neurogenic causes of scalp dysesthesia occur with damage to the central or peripheral pathways of itch sensation, resulting in modification and heightened sensitivity of nerves that result in abnormal sensations in the absence of or out of proportion to external stimuli. A comprehensive review of etiologies is provided here, ranging from lesions to the central nervous system caused by cervical spine disease, trigeminal trophic syndrome, tumor, stroke, and multiple sclerosis, to small fiber neuropathies caused by diabetes, brow lifts, keloid and burn scarring. Recently, there have also been reports of scalp dysesthesias associated with post-infectious COVID-19. Treatment options tailored towards disease severity and different causes of disease will also be discussed. By elucidating the different mechanisms and therapeutic treatments of scalp dysesthesia, we hope to provide clinicians with the tools to identify and treat this condition as well as encourage further research into its etiologies and therapeutics.

[Design and application method of a rapid cooling device for burns in field battle training]

At present, there is no special rapid cooling device for burn injury site in field battle training environment. To solve this problem, our research team designed a rapid cooling device for burns in field battle training. Based on the principle of rapid cooling of liquid nitrogen, the device monitors the temperature of the wound surface to regulate the release of liquid nitrogen so as to reduce the wound temperature. The device is simple in design, light in material, small in size, easy to carry, and can be used in various parts of the body. In addition, it is easy to operate and is expected to deliver a rapid cooling effect on the burn injury site to avoid the secondary damage caused by heat conduction to deep tissue.

LncRNA ASB16-AS1 promotes proliferation and inhibits apoptosis of non small cell lung cancer cells by activating the Wnt/β catenin signaling pathway

OBJECTIVE

To detect the expression of long non-coding ribonucleic acid (lncRNA) ASB16-AS1 in non-small cell lung cancer (NSCLC) tissues and cells, and to explore the effect of lncRNA ASB16-AS1 on the biological functions of NSCLC cells.

PATIENTS AND METHODS

The expression level of lncRNA ASB16-AS1 in NSCLC tissues and cells was detected via real-time fluorescence quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR). The interference sequences of lncRNA ASB16-AS1 were designed and synthesized, and its transfection efficacy was detected by qRT-PCR. After knockdown of lncRNA ASB16-AS1, the proliferation, cell cycle, and apoptosis of NSCLC cells were detected via cell counting kit-8 (CCK-8) assay, colony formation assay, and flow cytometry, respectively. Moreover, the expression changes in the Wnt/β catenin signaling pathway were detected via Western blotting.

RESULTS

LncRNA ASB16-AS1 was upregulated in NSCLC tissues and cells compared with that in paracarcinoma tissues and 16HBE cells. The results of CCK-8 assay and colony formation assay revealed that the silence of lncRNA ASB16-AS1 attenuated the proliferative ability in NSCLC. The results of flow cytometry manifested that the silence of lncRNA ASB16-AS1 arrested the cell cycle in G0/1 phase, and accelerated the apoptosis rate. The key proteins in the Wnt/β-catenin signaling pathway were regulated by lncRNA ASB16-AS1 in NSCLC.

CONCLUSIONS

LncRNA ASB16-AS1 is upregulated in NSCLC tissues and cells, which promotes proliferation and inhibits apoptosis of NSCLC cells through the Wnt/β-catenin signaling pathway.

Time-correlated Single Ion Counting Mass Spectrometer with Long and Short Time-of-Flight Tubes and an Evaluation of Its Performance for Use in Trace Analysis of Allergenic Substances

An analyte molecule was ionized using a femtosecond laser as the ionization source and was measured by a twin-type time-of-flight mass spectrometer with long (42 cm) and short (6.4 cm) flight tubes. The signal was measured using an analog signal digitizer and a time-correlated single ion counting system, and performance was evaluated by comparing data obtained from both instruments. The short mass spectrometer had a mass resolution of 450 and was used in the trace analysis of allergenic substances in a fragrance.

The preparation of a novel iron/manganese binary oxide for the efficient removal of hexavalent chromium [Cr(vi)] from aqueous solutions

To remove hexavalent chromium Cr(vi) efficiently, a novel Fe–Mn binary oxide adsorbent was prepared via a “two-step method” combined with a co-precipitation method and hydrothermal method. The as-prepared Fe–Mn binary oxide absorbent was characterized via transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectra (FTIR), thermogravimetric analysis (TGA), zeta potential, BET and X-ray photoelectron spectroscopy (XPS). The results indicated that the morphology of the adsorbent was rod-like with length of about 100 nm and width of about 50–60 nm, specific surface area was 63.297 m² g⁻¹, has the composition of α-Fe₂O₃, β-MnO₂ and MnFe₂O₄ and isoelectric point was observed at pH value of 4.81. The removal of Cr(vi) was chosen as a model reaction to evaluate the adsorption capacity of the Fe–Mn binary oxide adsorbent, indicating that the Fe–Mn binary oxide adsorbent showed high adsorption performance (removal rate = 99%) and excellent adsorption stability (removal rate > 90% after six rounds of adsorption). The adsorption behavior of the Fe–Mn binary oxide was better represented by the Freundlich model (adsorption isotherm) and the pseudo-second-order model (adsorption kinetic), suggesting that the adsorption process was multi-molecular layer chemical adsorption. The possible adsorption mechanism of the Fe–Mn binary oxide for the removal of Cr(vi) included the protonation process and the electrostatic attraction interactions.

A novel Fe–Mn binary oxide adsorbent prepared via “co-precipitation and hydrothermal” method, for the efficient and fast removal of Cr(vi).

The effect of postoperative radiotherapy on the survival of patients with resectable stage III-N2 non-small-cell lung cancer: a systematic review and meta-analysis

In the potentially resectable cases of stage III-N2 non-small-cell lung cancer (NSCLC), the optimal post-operative treatment regimen for these patients is uncertain and post-operative radiation therapy (PORT) with chemotherapy is typically recommended. Our aim was to reassess the data of PORT on overall survival (OS) and disease-free survival (DFS) in stage III-N2 NSCLC, in order to figure out whether PORT might lead to a moderate improvement in local control and survival besides resection and adjuvant chemotherapy. A comprehensive search strategy was performed in EMBASE, PubMed, and Cochrane Library for relevant studies comparing PORT combined with adjuvant chemotherapy or adjuvant chemotherapy alone on OS and DFS in resectable stage III-N2 NSCLC. Data were extracted to estimate the effects of PORT on OS and DFS. Eleven studies with 8,928 patients were included. This meta-analysis demonstrated a trend in improving OS associated with the use of PORT (HR=0.88; 95% CI, 0.76 to 1.03; p=0.11) and a significantly difference of effect on DFS associated with the use of PORT (HR=0.78; 95% CI, 0.66 to 0.92; p=0.003). In a subgroup analysis on Caucasian patients, there was a statistically significant benefit (HR=0.88; 95% CI, 0.81 to 0.96; p=0.003) on OS for PORT. Our findings demonstrate that in the postoperative treatment for patients with stage III-N2 NSCLC, PORT is associated with improved OS and leads to a significantly increased DFS.

Establishing a model for childhood obesity in adolescent pigs

OBJECTIVE

Rising worldwide prevalence of obesity and metabolic diseases in children has accentuated the importance of developing prevention and management strategies. The objective of this study was to establish a model for childhood obesity using high-fat feeding of adolescent pigs, as pigs have a longer developmental period and are physiologically more similar to humans than rodents.

METHODS

Crossbred pigs were fed a high-fat diet (HFD) or low-fat diet (n = 6/treatment) from postnatal day 49 to 84. On postnatal day 84, an oral glucose tolerance test was performed, jugular blood sampled to determine lipopolysaccharide levels and plasma lipids, intestinal digesta collected to characterize microbial and metabolite composition and back fat and intestinal tissue assayed for gene expression.

RESULTS

Five-week HFD increased weight gain and back fat thickness, caused dyslipidaemia and impaired glucose tolerance and increased expression of genes in back fat suggesting inflammation. HFD pigs had distinct proximal colon microbiota with 48% reduction (P < 0.05) in Bacteroidetes and increased expression of pro-inflammatory genes interleukin-18 and tumour necrosis factor in ileum (P < 0.05).

CONCLUSIONS

These findings indicate that adolescent pigs should be considered a suitable model for childhood obesity, because short-term HFD feeding is sufficient to induce obesity and glucose intolerance, recapitulating disease characteristics in adolescent pigs.

Separation of Two Distinct O-Glycoforms of Human IgA1 by Serial Lectin Chromatography Followed by Mass Spectrometry O-Glycan Analysis

Human immunoglobulin A1 (IgA1), which carries four to six mucin-type O-glycans (O-glycans) on its hinge region (HR), is the most abundant O-glycoprotein in plasma or serum. While normal O-glycans from hematopoietic-originated cells are core 1-based complex structures, many reports showed that the IgA1 from patients with IgA nephropathy (IgAN) carries undergalactosylated or truncated O-glycans such as the Tn antigen and its sialylated version the SialylTn (STn) antigen on the HR. Yet, there is still a debate whether Tn/STn on the HR of IgA1 is specific to the IgA1 from patients with IgAN since these antigens have also been seen in serum IgA1 of healthy individuals. An additional question is whether the O-glycans at all sites on the two HRs of one IgA1 molecule are homogeneous (either all normal or all Tn/STn) or heterogeneous (both normal and Tn/STn O-glycans). To address these questions, we conducted a systematic study on the O-glycans of plasma IgA1 from both IgAN patients and healthy controls using serial HPA and PNA lectin chromatography followed by western blotting and further analysis of O-glycans from HPA-bound and PNA-bound IgA1 fractions by mass spectrometry. Unexpectedly, we found that a variable minor fraction of IgA1 from both IgAN patients and healthy controls had Tn/STn antigens, and that the O-glycoprotein IgA1 molecules from most samples had only two distinct O-glycoforms: one major glycoform with homogeneous normal core 1-based O-glycans and one minor glycoform with homogeneous Tn/STn antigens. These results raised a serious question about the role of Tn/STn antigens on IgA1 in pathogenesis of IgAN, and there is a demand for a practical methodology that any laboratory can utilize to analyze the O-glycans of IgA1. Herein, we describe the methodology we developed in more detail. The method could also be applied to the analysis of any other O-glycosylated proteins.

Next-generation sequencing of Chinese stage IV lung cancer patients reveals an association between EGFR mutation status and survival outcome

Large-scale genomic characterization of non-small cell lung cancer (NSCLC) has revealed several putative oncogenic driver mutations that may constitute druggable therapeutic targets. However, there are little data to suggest that such gene alterations have clinical relevance. Over 12 consecutive months, tumor biopsy samples from 80 patients with stage IV NSCLC were analyzed for mutations in selected exons of 508 cancer-related genes using next-generation sequencing. From 85 specimens referred for genomic characterization, 80 (94%) specimens were successfully genotyped, and all had identifiable somatic alterations. Epidermal growth factor receptor (EGFR) and TP53 genes contained the highest frequency of observed mutations (65% and 40%, respectively) in the stage IV NSCLC cases. Notably, patients with EGFR mutations showed a significantly shorter survival time compared with patients expressing wild-type EGFR (p = 0.0053). Moreover, of the 32 patients harboring EGFR mutations, EGFR-L858R mutant patients showed a significantly shorter survival time compared with patients with other EGFR mutations (p = 0.036). In conclusion, tumors from stage IV NSCLC patients harbor characteristic gene alterations, of which EGFR L858R in particular appears to be a poor prognostic factor for overall survival.

A photoactivatable Src homology 2 (SH2) domain

A photoactivatable SH2 domain that can be potentially applied as an optogenetic tool to the photocontrol of phosphotyrosine-associated biological processes.

A semiautomated approach for artefact removal in serial tissue cryosections

Thinly sliced serial tissue sections of an organ can be imaged using optical microscopy at a resolution detailing individual cells. When the tissue sections are first subjected to in situ hybridization or immunohistochemistry, these data sets can be analysed for changes in gene expression and gene products. Such spatial information is important for understanding the functional effects of experimental or environmental challenges to the organism. However, a critical step in analysing these data sets is mitigating artefacts that result from the preparation of the tissue sections. In this paper, we describe an automated method with manual validation tools that together enable detecting and addressing artefacts including dust particles and air bubbles.

Semi-isometric registration of line features for flexible fitting of protein structures

In this paper, we study a registration problem that is motivated by a practical biology problem - fitting protein structures to low-resolution density maps. We consider registration between two sets of lines features (e.g., helices in the proteins) that have undergone not a single, but multiple isometric transformations (e.g., hinge-motions). The problem is further complicated by the presence of symmetry in each set. We formulate the problem as a clique-finding problem in a product graph, and propose a heuristic solution that includes a fast clique-finding algorithm unique to the structure of this graph. When tested on a suite of real protein structures, the algorithm achieved high accuracy even for very large inputs containing hundreds of helices.

Surface Reconstruction From Non-parallel Curve Networks

Building surfaces from cross-section curves has wide applications including bio-medical modeling. Previous work in this area has mostly focused on connecting simple closed curves on parallel cross-sections. Here we consider the more general problem where input data may lie on non-parallel cross-sections and consist of curve networks that represent the segmentation of the underlying object by different material or tissue types (e.g., skin, muscle, bone, etc.) on each cross-section. The desired output is a surface network that models both the exterior surface and the internal partitioning of the object. We introduce an algorithm that is capable of handling curve networks of arbitrary shape and topology on cross-section planes with arbitrary orientations. Our algorithm is simple to implement and is guaranteed to produce a closed surface network that interpolates the curve network on each cross-section. Our method is demonstrated on both synthetic and bio-medical examples.

Automated characterization of gene expression patterns with an atlas of the mouse brain

A spatio-temporal map of gene activity in the brain would be an important contribution to the understanding of brain development, disease, and function. Such a resource is now possible using high-throughput in situ hybridization, a method for transcriptome-wide acquisition of cellular resolution gene expression patterns in serial tissue sections. However, querying an enormous quantity of image data requires computational methods for describing and organizing gene expression patterns in a consistent manner. In addressing this, we have developed procedures for automated annotation of gene expression patterns in the postnatal mouse brain.

A novel glycosulfopeptide binds to P-selectin and inhibits leukocyte adhesion to P-selectin

P-selectin glycoprotein ligand-1 (PSGL-1) is a dimeric membrane mucin on leukocytes that binds selectins. The molecular features of PSGL-1 that determine this high affinity binding are unclear. Here we demonstrate the in vitro synthesis of a novel glycosulfopeptide (GSP-6) modeled after the extreme N terminus of PSGL-1, which has been predicted to be important for P-selectin binding. GSP-6 contains three tyrosine sulfate (TyrSO(3)) residues and a monosialylated, core 2-based O-glycan with a sialyl Lewis x (C2-O-sLe(x)) motif at a specific Thr residue. GSP-6 binds tightly to immobilized P-selectin, whereas glycopeptides lacking either TyrSO(3) or C2-O-sLe(x) do not detectably bind. Remarkably, an isomeric glycosulfopeptide to GSP-6, termed GSP-6', which contains sLe(x) on an extended core 1-based O-glycan, does not bind immobilized P-selectin. Equilibrium gel filtration analysis revealed that GSP-6 binds to soluble P-selectin with a K(d) of approximately 350 nM. GSP-6 (<5 microM) substantially inhibits neutrophil adhesion to P-selectin in vitro, whereas free sLe(x) (5 mM) only slightly inhibits adhesion. In contrast to the inherent heterogeneity of post-translational modifications of recombinant proteins, glycosulfopeptides permit the placement of sulfate groups and glycans of precise structure at defined positions on a polypeptide. This approach should expedite the probing of structure-function relationships in sulfated and glycosylated proteins, and may facilitate development of novel drugs to treat inflammatory diseases involving P-selectin-mediated leukocyte adhesion.