FEBS Open Bio最新文献

Diabetic cardiomyopathy (DCM) is pathologically characterized by excessive deposition of extracellular matrix proteins, leading to myocardial fibrosis. Fibromodulin (Fmod) plays a crucial role in the pathogenesis of fibrotic diseases. However, the role and mechanism of Fmod in DCM-related myocardial fibrosis remain unclear. In the present study, we established a DCM rat model and an in vitro model of rat primary cardiac fibroblasts (RPCFs) exposed to high glucose. We assessed mRNA and protein expression levels of Col1a1, Col3a1, α-SMA and Fmod in both models. Fmod-overexpressing (ov-Fmod) and Fmod-knockdown (si-Fmod) rat cardiac fibroblasts (RCFs) were generated. Subsequently, whole RNA sequencing was conducted on ov-Fmod RCFs. The gene Col15a1 was evaluated in the DCM rat and all cell models. The correlation between plasma levels of Fmod and Col15a1 in DCM rat models was assessed. Transcription and protein levels of Fmod, Col1a1, Col3a1 and α-SMA were significantly elevated in DCM rat hearts and RPCFs. In ov-Fmod RCFs, fibrosis markers were similarly increased, except for Col3a1, which decreased. The Col1a1/Col3a1 ratio was elevated. Conversely, knocking down Fmod yielded opposite results. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses indicated that Fmod participates in multiple fibrosis-related pathways, affecting Col15a1. Expression of Col15a1 was significantly decreased in all models, compared to controls, except in si-Fmod RCFs. Importantly, Col15a1 and Fmod in plasma exhibited an inverse relationship in DCM. In summary, Fmod is implicated in DCM, with Fmod overexpression downregulating Col15a1 and increasing the Col1a1/Col3a1 ratio. This mechanism may influence diastolic heart failure in DCM by modulating myocardial stiffness and elasticity.

Obesity, a global health concern, results from an energy imbalance leading to lipid accumulation. In the present study, Cordyceps militaris extract (CM) and its primary component, cordycepin, were investigated to characterize their potential effects on adipogenesis and lipolysis. Treatment with CM or cordycepin reduced lipid droplets and increased hormone-sensitive lipase activation in 3T3-L1 cells. In a diabetic obese mouse model, CM and cordycepin lowered serum low-density lipoprotein/very low-density lipoprotein levels and reduced oxidative stress and cell senescence markers. Thus, cordycepin inhibits preadipocyte differentiation and promotes lipolysis, which may serve as a novel obesity treatment. Further studies, including clinical trials, are required to validate the clinical potential of cordycepin.

The production of high-quality crystals is a key step in crystallography in general, but control of crystallization conditions is even more crucial in serial crystallography, which requires sets of crystals homogeneous in size and diffraction properties. This protocol describes the implementation of a simple and user-friendly microfluidic device that allows both the production of crystals by the counter-diffusion method and their in situ analysis by serial crystallography. As an illustration, the whole procedure is used to determine the crystal structure of three proteins from data collected at room temperature at a synchrotron radiation source.

The stonefish Synanceia verrucosa and Synanceia horrida are arguably the most venomous fish species on earth and the culprits of severe stings in humans globally. Investigation into the venoms of these two species has mainly focused on protein composition, in an attempt to identify the most medically relevant proteins, such as the lethal verrucotoxin and stonustoxin components. This study, however, focused on medically relevant small molecules, and through nuclear magnetic resonance, mass spectroscopy, and fractionation techniques, we discovered and identified the presence of three molecules new to stonefish venom, namely γ-aminobutyric acid (GABA), choline and 0-acetylcholine, and provide the first report of GABA identified in a fish venom. Analysis of the crude venoms on human nicotinic acetylcholine receptors (nAChRs) and a GABA_A receptor (GABA_AR) showed S. horrida venom could activate neuronal (α7) and adult muscle-type (α1β1δε) nAChRs, while both crude S. horrida and S. verrucosa venoms activated the GABA_AR (α1β2γ2). Cytotoxicity studies in immunologically relevant cells (human PBMCs) indicated the venoms possess cell-specific cytotoxicity and analysis of the venom fractions on Na⁺ channel subtypes involved in pain showed no activity. This work highlights the need to further investigate the small molecules found in venoms to help understand the mechanistic pathways of clinical symptoms for improved treatment of sting victims, in addition to the discovery of potential drug leads.

Sea stars are an abundant group of marine invertebrates that display remarkably robust regenerative capabilities throughout all life stages. Numerous proteins and peptides have been identified in a proteome study on the coelomic fluid (biofluid) of the common sea star Asterias rubens, which appear to be involved with the wound-healing response in the organism. However, the three-dimensional structure and function of several of these injury-responsive peptides, including the peptide KASH2, are yet to be investigated. Here, we show that the KASH2 peptide adopts a disulfide-directed β-hairpin fold (DDH). The DDH motif appears to be evolutionarily related to the inhibitor cystine knot motif, which is one of the most widespread disulfide-rich peptide folds. The DDH motif was originally thought to be restricted to arachnids, but our study suggests that as a result of convergent evolution it could also have originated in sea stars. Although the widely conserved DDH fold has potential cross-phyla wound-healing capacity, we have shown that KASH2 does not enhance the proliferation of human fibroblasts, a simple method for wound-healing re-epithelialisation screening. Therefore, additional research is necessary to determine the role of KASH2 in the sea stars.

Glucose-6-phosphatase-β (G6PC3) is a ubiquitous phosphatase present in the endoplasmic reticulum, which, unlike G6PC1, is not responsible for maintaining blood glucose level under starvation. Recently, G6PC3 has been shown to play an important role in neutrophil granulocytes, eliminating the toxic metabolite 1,5-anhydroglucitol-6-phosphate. The present study aimed to look for alternative substrates for the enzyme and outline the expression changes in the parts of this multicomponent system during neutrophil granulocyte differentiation. We determined the kinetic characteristics of recombinant human G6PC3 towards different sugar phosphates, and the transport of these compounds was also measured in rat liver microsomes. We found that all investigated sugar phosphates are substrates for G6PC3, although their microsomal transport is much slower than that of glucose-6-phosphate. Using the HL-60 promyelocytic leukemia cell line as an in vitro model system for myeloid differentiation, we found no significant differences in enzyme expression and phosphatase activity latency between undifferentiated and differentiated cells. Our results provide novel insights into the possible role of G6PC3 in the dephosphorylation of alternative sugar phosphates or their metabolites synthesized in the endoplasmic reticulum and confirm the potential feature of the enzyme in the promyelocytic stage as well. These findings contribute to our knowledge of intracellular carbohydrate metabolism of neutrophil granulocytes, which facilitates further research directions to better understand the underlying mechanisms of neutropenias.

The tumor microenvironment (TME) is well known for its immune suppressive role, especially in solid tumors which are characterized by a thick, dense stroma. Apart from cell-cell interactions and biochemical signals, the tumor stroma is also characterized by its distinct mechanical properties, which are dictated by the composition and architecture of its extracellular matrix (ECM). Cancer-associated fibroblasts (CAFs) are the main producers and remodelers of the stromal ECM, and their heterogeneity has recently become a focus of intense research. This review describes recent findings highlighting CAF subtypes and their specific functions, as well as the development of 3D models to study tumor stroma mechanics in vitro. Finally, we discuss the quantitative techniques used to measure tissue mechanical properties at different scales. Given the diagnostic and prognostic value of stroma stiffness and composition, and the recent development of anti-tumor therapeutic strategies targeting the stroma, understanding and measuring tumor stroma mechanical properties has never been more timely or relevant.

Teamwork is vital to all types of work, and graduates of higher education programmes must be prepared to contribute to a wide variety of professional teams. This is especially true in healthcare, where graduates will work in multidisciplinary teams (MDTs) under considerable pressure. This study is a follow-up to a previous study, where we described how competition between students is a barrier to constructive teamwork. Since then, we have made considerable enhancements to our transferable skills curriculum, moved away from norm referencing, and there have been national changes to the way that graduate Foundation training places are allocated. Here we present findings from a qualitative study of students from all six stages of our medical degree programme (5 years plus predegree foundation year). We explored whether there had been changes in how students perceived the importance of teamwork, their own teamwork development and how they collaborated with their peers. Following analysis of in-depth, semi-structured interviews, five themes emerged: (a) competition between students; (b) importance of teamwork; (c) what makes effective teamwork; (d) preparing for work in MDTs; and (e) recommendations for teamwork education. Competition between students was perceived as both positive and negative, but there has been a shift since our last study towards collaboration, with students now more willing to help each other succeed. Students also show more insight into their teamwork development, and were able to discuss what aspects of the programme, and higher education more broadly, were most valuable in helping them develop.

Thermal heating of biological samples allows to reversibly manipulate cellular processes with high temporal and spatial resolution. Manifold heating techniques in combination with live-cell imaging were developed, commonly tailored to customized applications. They include Peltier elements and microfluidics for homogenous sample heating as well as infrared lasers and radiation absorption by nanostructures for spot heating. A prerequisite of all techniques is that the induced temperature changes are measured precisely which can be the main challenge considering subcellular structures or multicellular organisms as target regions. This article discusses heating and temperature sensing techniques for live-cell imaging, leading to future applications in cell biology.

RETRACTION: Y. Sheng, J. Zhang, K. Li, H. Wang, W. Wang, L. Wen, J. Gao, X. Tang, H. Tang, H. Huang, M. Cai, T. Yuan, L. Liu, X. Zheng, Z. Zhu and Y. Cui, “Bach2 Overexpression Represses Th9 Cell Differentiation by Suppressing IRF4 Expression in Systemic Lupus Erythematosus,” FEBS Open Bio 11, no. 2 (2021): 395–403, https://doi.org/10.1002/2211-5463.13050.

The above article, published online on 28 November 2020 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the authors; the journal Editor-in-Chief, Miguel A. De la Rosa; FEBS Press; and John Wiley and Sons Ltd. The retraction has been agreed following diagnostic errors identified by the authors in the patient samples used in this study. Based on the issues identified, the editors and authors consider the conclusions substantially compromised.