AI-assisted mass spectrometry imaging with in situ image segmentation for subcellular metabolomics analysis.

Subcellular metabolomics analysis is crucial for understanding intracellular heterogeneity and accurate drug-cell interactions. Unfortunately, the ultra-small size and complex microenvironment inside the cell pose a great challenge to achieving this goal. To address this challenge, we propose an artificial intelligence-assisted subcellular mass spectrometry imaging (AI-SMSI) strategy with in situ image segmentation. Based on the nanometer-resolution MSI technique, the protonated guanine and threonine ions were respectively employed as the nucleus and cytoplasmic markers to complete image segmentation at the subcellular level, avoiding mutual interference of signals from various compartments in the cell. With advanced AI models, the metabolites within the different regions could be further integrated and profiled. Through this method, we decrypted the distinct action mechanism of isomeric drugs, doxorubicin (DOX) and epirubicin (EPI), only with a stereochemical inversion at C-4'. Within the cytoplasmic region, fifteen specific metabolites were discovered as biomarkers for distinguishing the drug action difference between DOX and EPI. Moreover, we identified that the downregulations of glutamate and aspartate in the malate-aspartate shuttle pathway may contribute to the higher paratoxicity of DOX. Our current AI-SMSI approach has promising applications for subcellular metabolomics analysis and thus opens new opportunities to further explore drug-cell specific interactions for the long-term pursuit of precision medicine.

Ambient Temperature Affects Protein Self-Assembly by Interfering with the Interfacial Aggregation Behavior.

Amyloid fibrillation is known to be associated with degenerative diseases, and mature fibrils are also considered as valuable biomedical materials. Thus, the mechanism and influencing factors of fibrillation have always been the focus of research. However, in vitro studies are always plagued by low reproducibility of kinetics and the molecular mechanism of amyloid fibrillation is under debate until now. Here, we identified the ambient temperature (AT) as a non-negligible interfering factor in in vitro self-assembly of globular protein hen egg-white lysozyme for the first time. By multimodal molecular spectroscopy methods, not only the effect of ATs on the kinetics of protein aggregation was described but also the conformational changes of the molecular structure with different ATs were captured. Through investigating the dependence of interfacial area and catalysis, the reason for this influence was construed by the various aggregation behaviors of protein molecules in the two-phase interface. The results suggest that in vitro mechanism research on protein fibrillation needs to first clarify the AT for a more accurate comparative analysis. The proposal of this concept will provide a new clue for a deeper understanding of the mechanism of protein self-assembly and may have an impact on evaluating the efficiency of amyloid accelerators or inhibitors based on the comparative analysis of protein self-assembly.

Nanometer Resolution Mass Spectro-Microtomography for In-Depth Anatomical Profiling of Single Cells.

Visually identifying the molecular changes in single cells is of great importance for unraveling fundamental cellular functions as well as disease mechanisms. Herein, we demonstrated a mass spectro-microtomography with an optimal voxel resolution of ∼300 × 300 × 25 nm3, which enables three-dimensional tomography of chemical substances in single cells. This mass imaging method allows for the distinguishment of abundant endogenous and exogenous molecules in subcellular structures. Combined with statistical analysis, we demonstrated this method for spatial metabolomics analysis of drug distribution and subsequent molecular damages caused by intracellular drug action. More interestingly, thanks to the nanoprecision ablation depth (∼12 nm), we realized metabolomics profiling of cell membrane without the interference of cytoplasm and improved the distinction of cancer cells from normal cells. Our current method holds great potential to be a powerful tool for spatially resolved single-cell metabolomics analysis of chemical components during complex biological processes.

Case Report and Literature Review: Disseminated Histoplasmosis Infection Diagnosed by Metagenomic Next-Generation Sequencing.

Background: Histoplasmosis is a deep fungal infection caused by Histoplasma capsulatum and can be classified as pulmonary, disseminated or central. Disseminated histoplasmosis is the most dangerous of all clinical types and is characterized by rapid onset, rapid progression, high mortality, and difficulty in diagnosis and treatment. Case Presentation: This report describes a 31-year-old female who presented with fever, with a maximum temperature of 39.8 °C. There were no concomitant symptoms, such as cough, sputum, abdominal pain and diarrhoea, before the onset of fever, and the illness lasted for more than 20 days. On examination, the liver and spleen were enlarged, and laboratory tests showed a significant decrease in CD4 cell count, suggesting immune deficiency. Broad-spectrum antibiotic treatment was ineffective, and specific infectious diseases and haematological neoplasms were considered likely. She was finally diagnosed with disseminated histoplasmosis after undergoing bone marrow aspiration and metagenomic next-generation sequencing (mNGS) and was treated with amphotericin B, fluorouracil and itraconazole, with good results. Conclusion: This case demonstrates that disseminated histoplasmosis infection can present with unexplained fever and that mNGS can be an important complement to bone marrow aspiration for the diagnosis of this disease.

Molecular data provide new insights into the phylogeny of Cladonotinae (Orthoptera: Tetrigoidea) from China with the description of a new genus and species.

Considerable effort has been devoted to elucidating the phylogenetic relationships of tetrigides. However, there is still no commonly accepted phylogenetic hypothesis. Therefore, the phylogenetic relationships among some subfamilies remain unclear; e.g., Cladonotinae is a controversial group, in which the phylogenetic relationships between genera and the boundaries of some of the included genera are unclear, causing some of the taxa to be difficult to identify. Therefore, an in-depth phylogenetic analysis of Cladonotinae is urgently needed. In this study, a robust phylogenetic framework for the tetrigides was reconstructed based on the combined mitochondrial cytochrome oxidase subunit I (COI), 16S ribosomal RNA (16S rRNA), and nuclear 18S ribosomal RNA (18S rRNA) gene sequences of 25 species belonging to 16 genera of Tetrigoidea from China, which included 13 species from 8 genera of Cladonotinae. Phylogenetic inferences were performed using the combined dataset and Bayesian inference (BI) and Maximum Parsimony (MP) methods, and the phylogenetic tree of Cladonotinae was reconstructed. All inferences based on the results of the present study supported the Cladonotinae subfamily as a polyphyletic group; within the Cladonotinae subfamily, Tetradinodula, and Tuberfemurus were closely related to Tetriginae, while Austrohancockia and Gibbotettix showed a close relationship to the Scelimenidae subfamily. Additionally, a new genus and new species of the Cladonotinae subfamily are described and illustrated: Hainantettix Deng, gen. nov. and Hainantettix strictivertex Deng, sp. nov.

A review of the genus Systolederus Bolivar (Orthoptera: Metrodorinae) from China.

The tetrigid genus Systolederus Bolivar, 1887 from China is taxonomically reviewed. The genus now includes 16 species from China, in which one new species is described and illustrated, namely: Systolederus aspinus Deng, sp. nov.. Their distribution and an annotated identification key to Chinese species are provided.

An annotated catalogue of the pygmy grasshoppers of the genus Criotettix Bolívar, 1887 (Orthoptera: Tetrigidae) with two new Criotettix species from China.

The tetrigid genus Criotettix Bolívar, 1887 from China is taxonomically reviewed. The genus now includes 39 species from China, in which two new species are described and illustrated, namely: Criotettix longispinus Deng, sp. nov. and Criotettix undatifemurus Deng, sp. nov..Their distribution and an annotated identification key to Chinese species are provided.

Cdk5 is required for the neuroprotective effect of transforming growth factor-ß1 against cerebral ischemia-reperfusion.

Transforming Growth Factor ß1 (TGF-ß1), a well-known neuroprotective and neurotrophic factor in the central nervous system, is also involved in the repair process responses after ischemia-reperfusion injury. Herein, we found that TGF-ß1 enhanced Cdk5 expression while decreased Tunel-positive cells compared with the ischemia group, and roscovitine(Cdk5 inhibitor) treatment could blunt these effects. In vitro study, TGF-ß1 facilitated Cdk5/p35 complex, the proliferation, neurite growth and differentiation of PC12 cells, effects of which could be blunted by roscovitine and Cdk5 silencing. Moreover, ERK1/2 inhibitor SCH772984 abrogated the effects of TGF- ß1 on Cdk5 and Bax levels. Taken together, we conclude that Cdk5 contributes to the neuroprotective function of TGF- ß1 via ERK1/2 signaling.