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C/EBPβ is an intrinsically repressed transcription factor that regulates genes involved in differentiation, proliferation, tumorigenesis, and apoptosis. C/EBPβ acts as a repressor that is turned into an activator by the Ras oncoprotein through phosphorylation of a MAPK site. C/EBPβ activation is accompanied by a conformational change. Active and repressive C/EBPβ interacts with multisubunit Mediator complexes through the CRSP130/Sur2 subunit. The CRSP130/Sur2 subunit is common to two distinct types of Mediator complexes, characterized by CRSP70 and CDK8 proteins as transcriptionally active and inactive Mediator, respectively. Knockdown of CRSP130/Sur2 prevents Mediator binding and transactivation through C/EBPβ. Oncogenic Ras signaling or activating mutations in C/EBPβ selects the transcriptionally active Mediator complex that also associates with RNA polymerase II. These results show that a Ras-induced structural alteration of C/EBPβ determines differential gene activation through selective interaction with distinct Mediator complexes. [Copyright &y& Elsevier]

Background: Immune checkpoint inhibitors (ICIs) provide modest but unsatisfactory benefits for extensive-stage small cell lung cancer (ES-SCLC). Developing strategies for treating ES-SCLC is critical., Methods: We preliminarily explored the outcomes of salvage low-dose radiotherapy (LDRT) plus ICI on refractory SCLC patients. Next, we evaluated the combinational efficacy in murine SCLC. The tumor immune microenvironment (TIME) was analyzed for mechanistic study. Subsequently, we conducted a multicenter, prospective phase II trial that administered concurrent thoracic LDRT plus chemoimmunotherapy to treatment-naive ES-SCLC patients (MATCH trial, NCT04622228). The primary endpoint was confirmed objective response rate (ORR), and the key secondary endpoints included progression-free survival (PFS) and safety., Findings: Fifteen refractory SCLC patients treated with LDRT plus ICI were retrospectively reviewed. The ORR was 73.3% (95% confidence interval [CI], 44.9-92.2). We identified a specific dose of LDRT (15 Gy/5 fractions) that exhibited growth retardation and improved survival in murine SCLC when combined with ICIs. This combination recruited a special T cell population, TCF1 + PD-1 + CD8 + stem-like T cells, from tumor-draining lymph nodes into the TIME. The MATCH trial showed a confirmed ORR of 87.5% (95% CI, 75.9-94.8). The median PFS was 6.9 months (95% CI, 5.4-9.3)., Conclusions: These findings verified that LDRT plus chemoimmunotherapy was safe, feasible, and effective for ES-SCLC, warranting further investigation., Funding: This research was funded by West China Hospital (no. ZYJC21003), the National Natural Science Foundation of China (no. 82073336), and the MATCH trial was fully funded by Roche (China) Holding Ltd. (RCHL) and Shanghai Roche Pharmaceuticals Ltd. (SRPL)., Competing Interests: Declaration of interests Y. Lu has an invited speaker/project lead/principal investigator role with Roche, AstraZeneca, and BeiGene and an invited speaker role with Pfizer, Merck Sharp & Dohme, and Bristol-Myers Squibb. L.Z., Y. Zhang, M.H., Y.G., Y. Liu, J.Z., and B.Z. have an invited investigator role with Roche. J.S., C.X., H.W.,(9) L. Wu, Z. Yuan, N.B., M.F., and Yaping Xu have an invited principal investigator role with Roche., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Vesicle trafficking is a fundamental process that allows for the sorting and transport of specific proteins (i.e., "cargoes") to different compartments of eukaryotic cells. Cargo recognition primarily occurs through coats and the associated proteins at the donor membrane. However, it remains unclear whether cargoes can also be selected at other stages of vesicle trafficking to further enhance the fidelity of the process. The WDR11-FAM91A1 complex functions downstream of the clathrin-associated AP-1 complex to facilitate protein transport from endosomes to the TGN. Here, we report the cryo-EM structure of human WDR11-FAM91A1 complex. WDR11 directly and specifically recognizes a subset of acidic clusters, which we term super acidic clusters (SACs). WDR11 complex assembly and its binding to SAC-containing proteins are indispensable for the trafficking of SAC-containing proteins and proper neuronal development in zebrafish. Our studies thus uncover that cargo proteins could be recognized in a sequence-specific manner downstream of a protein coat., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 Elsevier Inc. All rights reserved.)

DOPEY2 has been shown to be associated with Down syndrome and PCDH7 might be involved in Rett syndrome and MECP2 duplication syndrome. The mechanism how both proteins play roles in these syndromes are largely unknown. Here, we show that Dopey2 and Pcdh7 balance the proliferation and differentiation of neural stem cells and progenitors during embryonic neurogenesis to generate proper size and architecture of zebrafish brains. Dopey2 and Pcdh7 mutually restricted expression of each other in zebrafish embryos. Dopey2 was responsible for the proliferation of neural stem cells/progenitors, whereas Pcdh7 was responsible for the differentiation of neural stem cells/progenitors. Both proteins were shown to orchestrate the proper development and arrangement of neural cells in zebrafish embryonic brains. The results provide an insight into mechanisms to understand how the embryonic brain is constituted and how developmental defects occur in the brains of patients with Down syndrome, Rett syndrome, or MECP2 duplication syndrome., Competing Interests: Authors declare that they have no competing interests., (© 2023 The Author(s).)

Bone stromal cells are critical for bone homeostasis and regeneration. Growing evidence suggests that non-stem bone niche cells support bone homeostasis and regeneration via paracrine mechanisms, which remain to be elucidated. Here, we show that physiologically quiescent SM22α-lineage stromal cells expand after bone injury to regulate diverse processes of intramembranous bone regeneration. The majority of SM22α-lineage cells neither act as stem cells in vivo nor show their expression patterns. Dysfunction of SM22α-lineage niche cells induced by loss of platelet-derived growth factor receptor β (PDGFRβ) impairs bone repair. We further show that PDGFRβ-triggered hydrogen sulfide (H 2 S) generation in SM22α-lineage niche cells facilitates osteogenesis and angiogenesis and suppresses overactive osteoclastogenesis. Collectively, these data demonstrate that non-stem SM22α-lineage niche cells support the niche for bone regeneration with a PDGFRβ/H 2 S-dependent regulatory mechanism. Our findings provide further insight into non-stem bone stromal niche cell populations and niche-regulation strategy for bone repair., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

CRISPR-associated protein 9 (Cas9)-mediated genome editing provides a promising cure for HIV-1/AIDS; however, gene delivery efficiency in vivo remains an obstacle to overcome. Here, we demonstrate the feasibility and efficiency of excising the HIV-1 provirus in three different animal models using an all-in-one adeno-associated virus (AAV) vector to deliver multiplex single-guide RNAs (sgRNAs) plus Staphylococcus aureus Cas9 (saCas9). The quadruplex sgRNAs/saCas9 vector outperformed the duplex vector in excising the integrated HIV-1 genome in cultured neural stem/progenitor cells from HIV-1 Tg26 transgenic mice. Intravenously injected quadruplex sgRNAs/saCas9 AAV-DJ/8 excised HIV-1 proviral DNA and significantly reduced viral RNA expression in several organs/tissues of Tg26 mice. In EcoHIV acutely infected mice, intravenously injected quadruplex sgRNAs/saCas9 AAV-DJ/8 reduced systemic EcoHIV infection, as determined by live bioluminescence imaging. Additionally, this quadruplex vector induced efficient proviral excision, as determined by PCR genotyping in the liver, lungs, brain, and spleen. Finally, in humanized bone marrow/liver/thymus (BLT) mice with chronic HIV-1 infection, successful proviral excision was detected by PCR genotyping in the spleen, lungs, heart, colon, and brain after a single intravenous injection of quadruplex sgRNAs/saCas9 AAV-DJ/8. In conclusion, in vivo excision of HIV-1 proviral DNA by sgRNAs/saCas9 in solid tissues/organs can be achieved via AAV delivery, a significant step toward human clinical trials., (Copyright © 2017 The American Society of Gene and Cell Therapy. Published by Elsevier Inc. All rights reserved.)

Radiation-induced lung injury (RILI) presents a common and major obstacle in the radiotherapy of thoracic cancers. The aim of this study was to examine whether RILI could be alleviated by mesenchymal stem cells (MSCs) expressing soluble transforming growth factor-β (TGF-β) type II receptor via an adenovirus (Ad-sTβR). Here, we systemically administered male MSCs into female mice challenged with thoracic irradiation. The data showed that either MSCs or Ad-sTβR transduced MSCs (Ad-sTβR-MSCs) specifically migrated into radiation-injured lung. Ad-sTβR-MSCs obviously alleviated lung injury, as reflected by survival and histopathology data, as well as the assays of malondialdehyde (MDA), hydroxyproline, plasma cytokines, and the expression of connective tissue growth factor (CTGF) and α-smooth muscle actin (α-SMA). Furthermore, MSCs and Ad-sTβR-MSCs could adopt the characteristics of alveolar type II (ATII) cells. However, the MSCs levels in the lungs were relatively low to account for the noted therapeutic effects, suggesting the presence of other mechanisms. In vivo, MSCs-conditioned medium (MSCs CM) significantly attenuated RILI. In vitro, MSCs CM protected ATII cells against radiation-induced apoptosis and DNA damage, and modulated the inflammatory response, indicating the beneficial effects of MSCs are largely due to its paracrine activity. Our results provide a novel insight for RILI therapy that currently lack efficient treatments.