A proximity labeling-based orthogonal trap strategy identifies HDAC8 promotes cell motility by modulating cortactin acetylation.

It is a challenge for the traditional affinity methods to capture transient interactions of enzyme-post-translational modification (PTM) substrates in vivo. Herein we presented a strategy termed proximity labeling-based orthogonal trap approach (ProLORT), relying upon APEX2-catalysed proximity labeling and an orthogonal trap pipeline as well as quantitative proteomics to directly investigate the transient interactome of enzyme-PTM substrates in living cells. As a proof of concept, ProLORT allows for robust evaluation of a known HDAC8 substrate, histone H3K9ac. By leveraging this approach, we identified numerous of putative acetylated proteins targeted by HDAC8, and further confirmed CTTN as a bona fide substrate in vivo. Next, we demonstrated that HDAC8 facilitates cell motility via deacetylation of CTTN at lysine 144 that attenuates its interaction with F-actin, expanding the underlying regulatory mechanisms of HDAC8. We developed a general strategy to profile the transient enzyme-substrate interactions mediated by PTMs, providing a powerful tool for identifying the spatiotemporal PTM-network regulated by enzymes in living cells.

A more accurate relationship between serum androgen and metabolism among healthy, nonobese, reproductive-age women based on liquid chromatography-tandem mass spectrometry.

This study explored a more precise association between androgens and glycolipid metabolism in healthy women of different ages. Body mass index (BMI), waist circumference (WC), and waist-to-hip ratio were used as body fat indicators. High-density lipoprotein (HDL), low-density lipoprotein, triglycerides, and total cholesterol were used as lipid markers. Fasting blood glucose (FBG), fasting insulin, and the homeostatic model assessment of insulin resistance were used to assess insulin resistance and glucose metabolism. Liquid chromatography-tandem mass spectrometry was used to measure androgen indicators, including testosterone, sex hormone-binding globulin (SHBG), free testosterone (FT), dihydrotestosterone (DHT), androstenedione (A4), dehydroepiandrosterone (DHEA), and dehydroepiandrosterone sulfate (DHEAS). DHEAS levels varied across age groups. Correlation analyses with Spearman's coefficient showed that the free androgen index correlated positively with WC (p = 0.040), FT correlated positively with BMI (p = 0.033) and WC (p = 0.049), SHBG correlated positively with HDL (p = 0.013), and A4 correlated positively with FBG (p = 0.017). Multiple linear regression analysis showed that among healthful women aged 36-40 years, A4 increased with FBG, and SHBG increased with HDL. Even within healthy, nonobese women, lipid and glucose metabolism were robustly correlated with androgens. Yearly metabolic assessments are necessary, particularly for FBG and HDL, since these markers can predict the likelihood of hyperandrogenemia, enabling timely interventions.

Whole course of treatment of autoimmune progesterone dermatitis that had spontaneously resolved during pregnancy: A case report and review of the literature.

Anaphylaxis due to autoimmune progesterone dermatitis is a rare but severe allergic disease in women. The clinical manifestations of APD are diverse, and a proper understanding of the disease can help even diagnose and treat it. A case of autoimmune progesterone dermatitis related in our department is reported as follows. She developed a rash with severe pruritus that was highly consistent with her menstrual cycle without any trigger 10 years ago. Laboratory tests were unremarkable. But all the symptoms disappeared during her pregnancy and resurfaced after the miscarriage. Two years ago, after a positive progesterone intradermal test confirmed the diagnosis of PH, she was given mifepristone, contraceptives(OCPs), and skin embedding treatment, and her symptoms improved.

Deciphering the Interactome of Histone Marks in Living Cells via Genetic Code Expansion Combined with Proximity Labeling.

Deciphering the endogenous interactors of histone post-translational modifications (hPTMs, also called histone marks) is essential to understand the mechanisms of epigenetic regulation. However, most of the analytical methods to determine hPTM interactomes are in vitro settings, lacking interrogating native chromatin. Although lysine crotonylation (Kcr) has recently been considered an important hPTM for the regulation of gene transcription, the interactors of Kcr still remain to be explored. Herein, we present a general approach relying upon a genetic code expansion system, APEX2 (engineered peroxidase)-mediated proximity labeling, and quantitative proteomics to profile interactomes of the selected hPTMs in living cells. We genetically fused APEX2 to the recombinant histone H3 with a crotonyl lysine inserted site specifically to generate APEX2-H3K9cr that incorporated into native chromatin. Upon activation, APEX2 triggered in vivo biotin labeling of H3K9cr interactors that can then be enriched with streptavidin beads and identified by mass spectrometry. Proteomic analysis further revealed the endogenous interactomes of H3K9cr and confirmed the reliability of the method. Moreover, DPF2 was identified as a candidate interactor, and the binding interaction of DPF2 to H3K9c was further characterized and verified. This study provides a novel strategy for the identification of hPTM interactomes in living cells, and we envision that this is key to elucidating epigenetic regulatory pathways.

Deciphering Risperidone-Induced Lipogenesis by Network Pharmacology and Molecular Validation.

Background: Risperidone is an atypical antipsychotic that can cause substantial weight gain. The pharmacological targets and molecular mechanisms related to risperidone-induced lipogenesis (RIL) remain to be elucidated. Therefore, network pharmacology and further experimental validation were undertaken to explore the action mechanisms of RIL. Methods: RILs were systematically analyzed by integrating multiple databases through integrated network pharmacology, transcriptomics, molecular docking, and molecular experiment analysis. The potential signaling pathways for RIL were identified and experimentally validated using gene ontology (GO) enrichment and Kyoto encyclopedia of genes and genomes (KEGG) analysis. Results: Risperidone promotes adipocyte differentiation and lipid accumulation through Oil Red O staining and reverse transcription-polymerase chain reaction (RT-PCR). After network pharmacology and GO analysis, risperidone was found to influence cellular metabolism. In addition, risperidone influences adipocyte metabolism, differentiation, and lipid accumulation-related functions through transcriptome analysis. Intersecting analysis, molecular docking, and pathway validation analysis showed that risperidone influences the adipocytokine signaling pathway by targeting MAPK14 (mitogen-activated protein kinase 14), MAPK8 (mitogen-activated protein kinase 8), and RXRA (retinoic acid receptor RXR-alpha), thereby inhibiting long-chain fatty acid ß-oxidation by decreasing STAT3 (signal transducer and activator of transcription 3) expression and phosphorylation. Conclusion: Risperidone increases adipocyte lipid accumulation by plausibly inhibiting long-chain fatty acid ß-oxidation through targeting MAPK14 and MAPK8.

DNA-guided photoactivatable probe-based chemical proteomics reveals the reader protein of mRNA methylation.

Chemical modification on mRNA can recruit specific binding proteins (readers/partners) to determine post-transcriptional gene regulation. However, the identification of the reader is extremely limited owing to the rather weak and highly dynamic non-covalent interactions between mRNA modification and reader, and therefore the sensitive and robust approaches are desirable. Here, we report a DNA-guided photoactivatable-based chemical proteomic approach for profiling the readers of mRNA methylation. By use of N6-methyladenosine (m6A), we illustrated that this method can be successfully utilized for labelling and enriching the readers of mRNA modification, as well as for the discovery of new partners. Thus we applied this strategy to a new modification 2'-O-methyladenosine. As a result, DDX1 was identified and verified as a potential binding protein. Our study therefore provides a powerful chemical proteomics tool for identifying the binding factors of mRNA modification and reveals the underlying function of mRNA modification.