The underlying mechanisms of thymocyte maturation remain largely unknown. Here, we report that serine/arginine-rich splicing factor 1 (SRSF1) intrinsically regulates the late stage of thymocyte development. Conditional deletion of SRSF1 resulted in severe defects in maintenance of late thymocyte survival and a blockade of the transition of TCRβhiCD24+CD69+ immature to TCRβhiCD24-CD69- mature thymocytes, corresponding to a notable reduction of recent thymic emigrants and diminished periphery T cell pool. Mechanistically, SRSF1 regulates the gene networks involved in thymocyte differentiation, proliferation, apoptosis, and type I interferon signaling pathway to safeguard T cell intrathymic maturation. In particular, SRSF1 directly binds and regulates Irf7 and Il27ra expression via alternative splicing in response to type I interferon signaling. Moreover, forced expression of interferon regulatory factor 7 rectifies the defects in SRSF1-deficient thymocyte maturation via restoring expression of type I interferon-related genes. Thus, our work provides new insight on SRSF1-mediated posttranscriptional regulatory mechanism of thymocyte development.

The EGFR-RAS-ERK pathway plays a key role in cancer development and progression. However, the integral assembly of EGFR-RAS-ERK signaling complexes from the upstream component EGFR to the downstream component ERK is largely unknown. Here, we show that hematopoietic PBX-interacting protein (HPIP) interacts with all classical components of the EGFR-RAS-ERK pathway and forms at least two complexes with overlapping components. Experiments of HPIP knockout or knockdown and chemical inhibition of HPIP expression showed that HPIP is required for EGFR-RAS-ERK signaling complex formation, EGFR-RAS-ERK signaling activation, and EGFR-RAS-ERK signaling-mediated promotion of aerobic glycolysis as well as cancer cell growth in vitro and in vivo. HPIP expression is correlated with EGFR-RAS-ERK signaling activation and predicts worse clinical outcomes in patients with lung cancer. These results provide insights into EGFR-RAS-ERK signaling complex formation and EGFR-RAS-ERK signaling regulation and suggest that HPIP may be a promising therapeutic target for cancer with dysregulated EGFR-RAS-ERK signaling.

Three-dimensional (3D) bioprinting of vascular tissues that are mechanically and functionally comparable to their native counterparts is an unmet challenge. Here, we developed a tough double-network hydrogel (bio)ink for microfluidic (bio)printing of mono- and dual-layered hollow conduits to recreate vein- and artery-like tissues, respectively. The tough hydrogel consisted of energy-dissipative ionically cross-linked alginate and elastic enzyme-cross-linked gelatin. The 3D bioprinted venous and arterial conduits exhibited key functionalities of respective vessels including relevant mechanical properties, perfusability, barrier performance, expressions of specific markers, and susceptibility to severe acute respiratory syndrome coronavirus 2 pseudo-viral infection. Notably, the arterial conduits revealed physiological vasoconstriction and vasodilatation responses. We further explored the feasibility of these conduits for vascular anastomosis. Together, our study presents biofabrication of mechanically and functionally relevant vascular conduits, showcasing their potentials as vascular models for disease studies in vitro and as grafts for vascular surgeries in vivo, possibly serving broad biomedical applications in the future.

Currently, the Cas9 and Cas12a systems are widely used for genome editing, but their ability to precisely generate large chromosome fragment deletions is limited. Type I-E CRISPR mediates broad and unidirectional DNA degradation, but controlling the size of Cas3-mediated DNA deletions has proven elusive thus far. Here, we demonstrate that the endonuclease deactivation of Cas9 (dCas9) can precisely control Cas3-mediated large-fragment deletions in mammalian cells. In addition, we report the elimination of the Y chromosome and precise retention of the Sry gene in mice using CRISPR/Cas3 and dCas9-controlled CRISPR/Cas3, respectively. In conclusion, dCas9-controlled CRISPR/Cas3-mediated precise large-fragment deletion provides an approach for establishing animal models by chromosome elimination. This method also holds promise as a potential therapeutic strategy for treating fragment mutations or human aneuploidy diseases that involve additional chromosomes.

The transient receptor potential canonical subfamily member 5 (TRPC5), one of seven mammalian TRPC members, is a nonselective calcium-permeant cation channel. TRPC5 is of considerable interest as a drug target in the treatment of progressive kidney disease, depression, and anxiety. Here, we present the 2.8-Å resolution cryo-electron microscopy (cryo-EM) structure of the mouse TRPC5 (mTRPC5) homotetramer. Comparison of the TRPC5 structure to previously determined structures of other TRPC and TRP channels reveals differences in the extracellular pore domain and in the length of the S3 helix. The disulfide bond at the extracellular side of the pore and a preceding small loop are essential elements for its proper function. This high-resolution structure of mTRPC5, combined with electrophysiology and mutagenesis, provides insight into the lipid modulation and gating mechanisms of the TRPC family of ion channels.

Structure-based molecular regulations have been widely adopted to modulate protein networks in cells and recently developed to control allosteric DNA operations in vitro. However, current examples of programmable allosteric signal transmission through integrated DNA networks are stringently constrained by specific design requirements. Developing a new, more general, and programmable scheme for establishing allosteric DNA networks remains challenging. Here, we developed a general strategy for programmable allosteric DNA regulations that can be finely tuned by varying the dimensions, positions, and number of conformational signals. By programming the allosteric signals, we realized fan-out/fan-in DNA gates and multiple-layer DNA cascading networks, as well as expanding the approach to long-range allosteric signal transmission through tunable DNA origami nanomachines ~100 nm in size. This strategy will enable programmable and complex allosteric DNA networks and nanodevices for nanoengineering, chemical, and biomedical applications displaying sense-compute-actuate molecular functionalities.

IL-6/STAT3 signaling is known to initiate the TH17 differentiation program, but the upstream regulatory mechanisms remain minimally explored. Here, we show that Cxxc finger protein 1 (Cxxc1) promoted the generation of TH17 cells as an epigenetic regulator and prevented their differentiation into Treg cells. Mice with a T cell-specific deletion of Cxxc1 were protected from experimental autoimmune encephalomyelitis and were more susceptible to Citrobacter rodentium infection. Cxxc1 deficiency decreased IL-6Rα expression and impeded IL-6/STAT3 signaling, whereas the overexpression of IL-6Rα could partially reverse the defects in Cxxc1-deficient TH17 cells in vitro and in vivo. Genome-wide occupancy analysis revealed that Cxxc1 bound to Il6rα gene loci by maintaining the appropriate H3K4me3 modification of its promoter. Therefore, these data highlight that Cxxc1 as a key regulator governs the balance between TH17 and Treg cells by controlling the expression of IL-6Rα, which affects IL-6/STAT3 signaling and has an impact on TH17-related autoimmune diseases.

Although vascular disrupting agents (VDAs) have been extensively implemented in current clinical tumor therapy, the notable adverse events caused by long-term dosing severely limit the therapeutic efficacy. To improve this therapy, we report a strategy for VDA-induced aggregation of gold nanoparticles to further destroy tumor vascular by photothermal effect. This strategy could effectively disrupt tumor vascular and cut off the nutrition supply after just one treatment. In the murine tumor model, this strategy results in notable tumor growth inhibition and gives rise to a 92.7% suppression of tumor growth. Besides, enhanced vascular damage could also prevent cancer cells from distant metastasis. Moreover, compared with clinical therapies, this strategy still exhibits preferable tumor suppression and metastasis inhibition ability. These results indicate that this strategy has great potential in tumor treatment and could effectively enhance tumor vascular damage and avoid the side effects caused by frequent administration.

Immune-responsive gene 1 (IRG1) encodes aconitate decarboxylase (ACOD1) that catalyzes the production of itaconic acids (ITAs). The anti-inflammatory function of IRG1/ITA has been established in multiple pathogen models, but very little is known in cancer. Here, we show that IRG1 is expressed in tumor-associated macrophages (TAMs) in both human and mouse tumors. Mechanistically, tumor cells induce Irg1 expression in macrophages by activating NF-κB pathway, and ITA produced by ACOD1 inhibits TET DNA dioxygenases to dampen the expression of inflammatory genes and the infiltration of CD8+ T cells into tumor sites. Deletion of Irg1 in mice suppresses the growth of multiple tumor types and enhances the efficacy of anti-PD-(L)1 immunotherapy. Our study provides a proof of concept that ACOD1 is a potential target for immune-oncology drugs and IRG1-deficient macrophages represent a potent cell therapy strategy for cancer treatment even in pancreatic tumors that are resistant to T cell-based immunotherapy.

Free fatty acid receptors 1 to 4 (FFA1 to FFA4) are class A G protein-coupled receptors (GPCRs). FFA1 to FFA3 share substantial sequence similarity, whereas FFA4 is unrelated. However, FFA1 and FFA4 are activated by long-chain fatty acids, while FFA2 and FFA3 respond to short-chain fatty acids generated by intestinal microbiota. FFA1, FFA2, and FFA4 are potential drug targets for metabolic and inflammatory conditions. Here, we determined the active structures of FFA1 and FFA4 bound to docosahexaenoic acid, FFA4 bound to the synthetic agonist TUG-891, and butyrate-bound FFA2, each complexed with an engineered heterotrimeric Gq protein (miniGq), by cryo-electron microscopy. Together with computational simulations and mutagenesis studies, we elucidated the similarities and differences in the binding modes of fatty acid ligands to their respective GPCRs. Our findings unveiled distinct mechanisms of receptor activation and G protein coupling. We anticipate that these outcomes will facilitate structure-based drug development and underpin future research on this group of GPCRs.

Advances in molecular profiling have opened up the possibility to map the expression of genes in cells, tissues, and organs in the human body. Here, we combined single-cell transcriptomics analysis with spatial antibody-based protein profiling to create a high-resolution single-cell type map of human tissues. An open access atlas has been launched to allow researchers to explore the expression of human protein-coding genes in 192 individual cell type clusters. An expression specificity classification was performed to determine the number of genes elevated in each cell type, allowing comparisons with bulk transcriptomics data. The analysis highlights distinct expression clusters corresponding to cell types sharing similar functions, both within the same organs and between organs.

Proinflammatory activation and accumulation of adipose tissue macrophages (ATMs) are associated with increased risk of insulin resistance in obesity. Here, we described the previously unidentified role of selenocysteine insertion sequence-binding protein 2 (SBP2) in maintaining insulin sensitivity in obesity. SBP2 was suppressed in ATMs of diet-induced obese mice and was correlated with adipose tissue inflammation. Loss of SBP2 initiated metabolic activation of ATMs, inducing intracellular reactive oxygen species content and inflammasome, which subsequently promoted IL-1β-associated local proliferation and infiltration of proinflammatory macrophages. ATM-specific knockdown of SBP2 in obese mice promoted insulin resistance by increasing fat tissue inflammation and expansion. Reexpression of SBP2 improved insulin sensitivity. Last, an herbal formula that specifically induced SBP2 expression in ATMs can experimentally improve insulin sensitivity. Clinical observation revealed that it improved hyperglycemia in patients with diabetes. This study identified SBP2 in ATMs as a potential target in rescuing insulin resistance in obesity.