Targeted Macrophage CRISPR-Cas13 mRNA Editing in Immunotherapy for Tendon Injury.

CRISPR-Cas13 holds substantial promise for tissue repair through its RNA editing capabilities and swift catabolism. However, conventional delivery methods fall short in addressing the heightened inflammatory response orchestrated by macrophages during the acute stages of tendon injury. In this investigation, macrophage-targeting cationic polymers are systematically screened to facilitate the entry of Cas13 ribonucleic-protein complex (Cas13 RNP) into macrophages. Notably, SPP1 (OPN encoding)-producing macrophages are recognized as a profibrotic subtype that emerges during the inflammatory stage. By employing ROS-responsive release mechanisms tailored for macrophage-targeted Cas13 RNP editing systems, the overactivation of SPP1 is curbed in the face of an acute immune microenvironment. Upon encapsulating this composite membrane around the tendon injury site, the macrophage-targeted Cas13 RNP effectively curtails the emergence of injury-induced SPP1-producing macrophages in the acute phase, leading to diminished fibroblast activation and mitigated peritendinous adhesion. Consequently, this study furnishes a swift RNA editing strategy for macrophages in the inflammatory phase triggered by ROS in tendon injury, along with a pioneering macrophage-targeted carrier proficient in delivering Cas13 into macrophages efficiently.

Significance of Gastrokine-1 Polymorphism Rs4254535 as a Prognostic Marker and its Association with Clinical Characteristics in Chinese Lung Cancer Patients.

Background: The single nucleotide polymorphism (SNP) of Gastrokine-1 (GKN1) is associated with lung cancer but its association with prognosis is not clear. Methods: Genomic DNA was extracted from the blood samples of 888 patients with lung cancer. The association between GKN1 polymorphism rs4254535 and prognostic was analyzed by the Kaplan-Meier (KM) method, Log-rank test, and Cox proportional hazards model. Results: In females and patients diagnosed with late-stage lung cancer, the CC genotype (CC vs TT, adjusted odds ratio [HR] = 0.57, 95% Confidence Interval [CI]: 0.33-0.99, P = 0.045; HR = 0.66, 95% CI: 0.48-0.92, P = 0.014) and recessive CC genotype (CC vs TT + TC, HR = 0.55, 95% CI: 0.32-0.94, P = 0.028; HR = 0.64, 95% CI: 0.47-0.89, P = 0.006) of rs4254535 conferred a better prognosis, compared with the TT and TT + TC genotype. Rs4254535 dominate TC + CC genotype, recessive CC genotype, and C allele who were adenocarcinoma patients had a significantly better prognosis. The recessive CC genotype of non-smoking patients has a better prognosis, compared to the TT + TC genotype. Additionally, in the dominant TT + TC genotype and C allele, no family history patients had a significantly better prognosis, compared to the TT genotype. Conclusion: For lung cancer patients, GKN1 polymorphism rs4254535 may be a protective genetic marker and predicts the prognosis of lung cancer patients.

A Blockchain-Based Traceability Model for Grain and Oil Food Supply Chain.

The structure of the grain-and-oil-food-supply chain has the characteristics of complexity, cross-regionality, a long cycle, and numerous participants, making it difficult to maintain the safety of supply. In recent years, some phenomena have emerged in the field of grain procurement and sale, such as topping the new with the old, rotating grains, the pressure of grades and prices, and counterfeit oil food, which have seriously threatened grain-and-oil-food security. Blockchain technology has the advantage of decentralization and non-tampering Therefore, this study analyzes the characteristics of traceability data in the grain-and-oil-food-supply chain, and presents a blockchain-based traceability model for the grain-and-oil-food-supply chain. Firstly, a new method combining blockchain and machine learning is proposed to enhance the authenticity and reliability of blockchain source data by constructing anomalous data-processing models. In addition, a lightweight blockchain-storage method and a data-recovery mechanism are proposed to reduce the pressure on supply-chain-data storage and improve fault tolerance. The results indicate that the average query delay of public data is 0.42 s, the average query delay of private data is 0.88 s, and the average data-recovery delay is 1.2 s. Finally, a blockchain-based grain-and-oil-food-supply-chain traceability system is designed and built using Hyperledger Fabric. Compared with the existing grain-and-oil-food-supply chain, the model constructed achieves multi-source heterogeneous data uploading, lightweight storage, data recovery, and traceability in the supply chain, which are of great significance for ensuring the safety of grain-and-oil food in China.

Prognostic implications of the EGFR polymorphism rs763317 and clinical variables among young Chinese lung cancer population.

The 5-year survival rate for patients with lung cancer, the world's second most frequent malignant tumor, is less than 20%, and its prognosis cannot be clearly predicted. Our aim was to analyze the epidermal growth factor receptor (EGFR) rs763317 (G>A) single nucleotide polymorphism and its association with prognosis in Chinese Han lung cancer patients. 839 patients with primary lung cancer were recruited, and genomic DNA was extracted and genotyped by SNPscan. Kaplan-Meier technique and multivariate Cox proportional hazards model were used to analyze the association between prognosis and EGFR polymorphism rs763317. A significant association after stratification by age, significantly increased lung cancer risk was associated with the AA homozygous genotype of rs763317 (adjusted hazard ratio = 2.53, 95% CI: 1.31-4.88, p=0.005), and conferred a poor survival for lung cancer patients (MST: median survival time: 13.6 months) compared with GG genotype (MST: 41.5 months), and in the recessive model AA genotype (AA vs. GG + GA; adjusted hazard ratio = 2.57, 95% CI: 1.34-4.93, p=0.004) who were young (<60 years) had a significantly increased risk of death. The EGFR polymorphism rs763617 might serve as a significant genetic marker for predicting the prognosis of lung cancer.

NLRP3-Dependent Crosstalk between Pyroptotic Macrophage and Senescent Cell Orchestrates Trauma-Induced Heterotopic Ossification During Aberrant Wound Healing.

Heterotopic ossification (HO) represents an unwanted ossific wound healing response to the soft tissue injury which caused catastrophic limb dysfunction. Recent studies established the involvement of inflammation and cellular senescence in the tissue healing process, though their role in HO still remained to be clarified. Here, a novel crosstalk where the pyroptotic macrophages aroused tendon-derived stem cells (TDSCs) senescence is revealed to encourage osteogenic healing during trauma-induced HO formation. Macrophage pyroptosis blockade reduces the senescent cell burden and HO formation in NLRP3 knockout mice. Pyroptosis-driven IL-1ß and extracellular vesicles (EVs) secretion from macrophages are determined to motivate TDSCs senescence and resultant osteogenesis. Mechanistically, pyroptosis in macrophages enhances the exosomal release of high mobility group protein 1 (HMGB1), which directly bounds TLR9 in TDSCs to trigger morbid signaling. NF-κB signaling is confirmed to be the converging downstream pathway of TDSCs in response to HMGB1-containing EVs and IL-1ß. This study adds insights into aberrant regeneration-based theory for HO formation and boosts therapeutic strategy development.

High-throughput site-specific N-glycoproteomics reveals glyco-signatures for liver disease diagnosis.

The glycoproteome has emerged as a prominent target for screening biomarkers, as altered glycosylation is a hallmark of cancer cells. In this work, we incorporated tandem mass tag labeling into quantitative glycoproteomics by developing a chemical labeling-assisted complementary dissociation method for the multiplexed analysis of intact N-glycopeptides. Benefiting from the complementary nature of two different mass spectrometry dissociation methods for identification and multiplex labeling for quantification of intact N-glycopeptides, we conducted the most comprehensive site-specific and subclass-specific N-glycosylation profiling of human serum immunoglobulin G (IgG) to date. By analysing the serum of 90 human patients with varying severities of liver diseases, as well as healthy controls, we identified that the combination of IgG1-H3N5F1 and IgG4-H4N3 can be used for distinguishing between different stages of liver diseases. Finally, we used targeted parallel reaction monitoring to successfully validate the expression changes of glycosylation in liver diseases in a different sample cohort that included 45 serum samples.

Sustained Release of Dicumarol via Novel Grafted Polymer in Electrospun Nanofiber Membrane for Treatment of Peritendinous Adhesion.

The prevention and treatment of post-traumatic peritendinous adhesion (PA) have always been a great difficulty for orthopedic surgeons. Current treatments include resecting surgery, non-steroidal anti-inflammatory drugs (NSAIDs) usage and implantable membranes, often target single disease pathogenic processes, resulting in unfavorable therapeutic outcomes. Here a polylactic acid (PLA)-dicumarol conjugates-electrospun nanofiber membrane (ENM) (PCD) is generated, which can achieve spatial accuracy and temporal sustainability in drug release. It is further demonstrated that PCD possesses a significantly higher and more sustainable drug release profile than traditional drug-loading ENM. By providing a physical barrier and continuous releasing of dicumarol, PCD implantation significantly reduces tissue adhesion by 25%, decreases fibroblasts activity and inhibits key fibrogenic cytokine transforming growth factor beta (TGFß) production by 30%, and improves the biomechanical tendon property by 14.69%. Mechanistically, PCD potently inhibits the connexin43 (Cx43) and thereby tunes down the fibroblastic TGFß/Smad3 signaling pathway. Thus, this approach leverages the anti-adhesion effect of dicumarol and drug release properties of grafted copolymer ENM by esters to provide a promising therapeutic strategy for patients who suffer from PA.

Alterations in bone fracture healing associated with TNFRSF signaling pathways.

Bone fracture healing is a complex process involving various signaling pathways. It remains an unsolved issue the fast and optimal management of complex or multiple fractures in the field of orthopedics and rehabilitation. Bone fracture healing is largely a four-stage process, including initial hematoma formation, intramembrane ossification, chondrogenesis, and endochondral ossification followed by further bone remodeling. Many studies have reported the involvement of immune cells and cytokines in fracture healing. On the other hand, the Tumor Necrosis Factor (TNF) family and TNF receptor superfamily (TNFRSF) play a pivotal role in many physiological processes. The functions of the TNF family and TNFRSF in immune processes, tissue homeostasis, and cell differentiation have been extensively studied by many groups, and treatments targeting specific TNFRSF members are in progress. In terms of bone fracture management, it has been discovered that several members of TNFRSF have very distinct functions in different stages of fracture healing, including TNFR1, TNFR2, and receptor activator of nuclear factor kappa-B (RANK) pathways. More specifically, TNFR1 is associated with osteoclastogenesis and TNFR2 is associated with osteogenic differentiation, while RANK is in association with bone remodeling. In this review, we will discuss and summarize the involvement of members of TNFRSF including TNFR1, TNFR2, and Receptor activator of nuclear factor kappa-B (RANK) pathways in different stages of fracture healing and bone remodeling and the current treatment trend involving TNFRSF agonists and antagonists.

The Roles of TNF Signaling Pathways in Metabolism of Bone Tumors.

The metabolism of bone tumors is extraordinarily complex and involves many signaling pathways and processes, including the tumor necrosis factor (TNF) signaling pathway, which consists of TNF factors and the TNF receptors that belong to the TNF receptor superfamily (TNFRSF). It is appreciated that signaling events and pathways involving TNFRSF components are essential in coordinating the functions of multiple cell types that act as a host defense network against pathogens and malignant cells, the implications of TNFRSF-related signaling pathways on bone tumor metabolism remain to be summarized, which is one of the significant obstacles to the application of TNF-related treatment modalities in the domain of bone oncology. This review will discuss and summarize the anti-tumor properties of important TNFRSF components concerning osteosarcoma, chondrosarcoma, and Ewing sarcoma.

The first case report of an intraosseous epidermoid cyst in the distal phalanx of the index finger with infection resulting in single clubbing finger: A case report and review of the literature.

An intraosseous epidermoid cyst at the distal phalanx of the index finger is extremely rare. These cysts are asymptomatic unless ruptured, severely infected, or transformed into malignant squamous cell carcinoma. We present a case of a single clubbing finger in an adult diagnosed with an intraosseous epidermoid cyst in the distal phalanx of the left index finger with no history of pulmonary or cardiovascular diseases. Preoperative MRI showed an expansile lytic lesion with a sclerotic margin. Histopathological examination indicates that there is keratinous cell debris in the cyst with a wall of stratified squamous epithelium, which was the key to the correct diagnosis of an intraosseous epidermoid cyst. Written informed consent was obtained from the patient for publication of this case report and any accompanying images.

Bi-directional regulation functions of lanthanum-substituted layered double hydroxide nanohybrid scaffolds via activating osteogenesis and inhibiting osteoclastogenesis for osteoporotic bone regeneration.

Rationale: Osteoporotic patients suffer symptoms of excessive osteoclastogenesis and impaired osteogenesis, resulting in a great challenge to treat osteoporosis-related bone defects. Based on the positive effect of rare earth elements on bone metabolism and bone regeneration, we try to prove the hypothesis that the La3+ dopants in lanthanum-substituted MgAl layered double hydroxide (La-LDH) nanohybrid scaffolds simultaneously activate osteogenesis and inhibit osteoclastogenesis. Methods: A freeze-drying technology was employed to construct La-LDH nanohybrid scaffolds. The in vitro osteogenic and anti-osteoclastogenic activities of La-LDH nanohybrid scaffolds were evaluated by using ovariectomized rat bone marrow stromal cells (rBMSCs-OVX) and bone marrow-derived macrophages (BMMs) as cell models. The in vivo bone regeneration ability of the scaffolds was investigated by using critical-size calvarial bone defect model of OVX rats. Results: La-LDH nanohybrid scaffolds exhibited three-dimensional macroporous structure, and La-LDH nanoplates arranged perpendicularly on chitosan organic matrix. The La3+ dopants in the scaffolds promote proliferation and osteogenic differentiation of rBMSCs-OVX by activating Wnt/ß-catenin pathway, leading to high expression of ALP, Runx-2, COL-1 and OCN genes. Moreover, La-LDH scaffolds significantly suppressed RANKL-induced osteoclastogenesis by inhibiting NF-κB signaling pathway. As compared with the scaffolds without La3+ dopants, La-LDH scaffolds provided more favourable microenvironment to induce new bone in-growth along macroporous channels. Conclusion: La-LDH nanohybrid scaffolds possessed the bi-directional regulation functions on osteogenesis and osteoclastogenesis for osteoporotic bone regeneration. The modification of La3+ dopants in bone scaffolds provides a novel strategy for osteoporosis-related bone defect healing.

Structural basis of the dynamic human CEACAM1 monomer-dimer equilibrium.

Human (h) carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) function depends upon IgV-mediated homodimerization or heterodimerization with host ligands, including hCEACAM5, hTIM-3, PD-1, and a variety of microbial pathogens. However, there is little structural information available on how hCEACAM1 transitions between monomeric and dimeric states which in the latter case is critical for initiating hCEACAM1 activities. We therefore mutated residues within the hCEACAM1 IgV GFCC' face including V39, I91, N97, and E99 and examined hCEACAM1 IgV monomer-homodimer exchange using differential scanning fluorimetry, multi-angle light scattering, X-ray crystallography and/or nuclear magnetic resonance. From these studies, we describe hCEACAM1 homodimeric, monomeric and transition states at atomic resolution and its conformational behavior in solution through NMR assignment of the wildtype (WT) hCEACAM1 IgV dimer and N97A mutant monomer. These studies reveal the flexibility of the GFCC' face and its important role in governing the formation of hCEACAM1 dimers and selective heterodimers.

Positive feedback regulation between USP15 and ERK2 inhibits osteoarthritis progression through TGF-ß/SMAD2 signaling.

BACKGROUND: The transforming growth factor-ß (TGF-ß) signaling pathway plays an essential role in maintaining homeostasis in joints affected by osteoarthritis (OA). However, the specific mechanism of non-SMAD and classical SMAD signaling interactions is still unclear, which needs to be further explored. METHODS: In ATDC5 cells, USP15 overexpression and knockout were performed using the transfected lentivirus USP15 and Crispr/Cas9. Western blotting and immunofluorescence staining were used to test p-SMAD2 and cartilage phenotype-related molecular markers. In rat OA models, immunohistochemistry, hematoxylin and eosin (HE)/Safranin-O fast green staining, and histology were used to examine the regulatory activity of USP15 in TGF-ß/SMAD2 signaling and the cartilage phenotype. Then, ERK2 overexpression and knockout were performed. The expressions of USP15, p-SMAD2, and the cartilage phenotype were evaluated in vitro and in vivo. To address whether USP15 is required for ERK2 and TGF-ß/SMAD2 signaling, we performed rescue experiments in vitro and in vivo. Immunoprecipitation and deubiquitination assays were used to examine whether USP15 could bind to ERK2 and affect the deubiquitination of ERK2. Finally, whether USP15 regulates the level of p-ERK1/2 was evaluated by western blotting, immunofluorescence staining, and immunohistochemistry in vitro and in vivo. RESULTS: Our results indicated that USP15 stimulated TGF-ß/SMAD2 signaling and the cartilage phenotype. Moreover, ERK2 required USP15 to influence TGF-ß/SMAD2 signaling for regulating the cartilage phenotype in vivo and in vitro. And USP15 can form a complex with ERK2 to regulate ubiquitination of ERK2. Interestingly, USP15 did not regulate the stability of ERK2 but increased the level of p-ERK1/2 to further enhance the TGF-ß/SMAD2 signaling pathway. CONCLUSIONS: Taken together, our study revealed positive feedback regulation between USP15 and ERK2, which played a critical role in TGF-ß/SMAD2 signaling to inhibit OA progression. Therefore, this specific mechanism can guide the clinical treatment of OA.

Direct Tumor Killing and Immunotherapy through Anti-SerpinB9 Therapy.

Cancer therapies kill tumors either directly or indirectly by evoking immune responses and have been combined with varying levels of success. Here, we describe a paradigm to control cancer growth that is based on both direct tumor killing and the triggering of protective immunity. Genetic ablation of serine protease inhibitor SerpinB9 (Sb9) results in the death of tumor cells in a granzyme B (GrB)-dependent manner. Sb9-deficient mice exhibited protective T cell-based host immunity to tumors in association with a decline in GrB-expressing immunosuppressive cells within the tumor microenvironment (TME). Maximal protection against tumor development was observed when the tumor and host were deficient in Sb9. The therapeutic utility of Sb9 inhibition was demonstrated by the control of tumor growth, resulting in increased survival times in mice. Our studies describe a molecular target that permits a combination of tumor ablation, interference within the TME, and immunotherapy in one potential modality.

The Recombinant Protein EphB4-Fc Changes the Ti Particle-Mediated Imbalance of OPG/RANKL via EphrinB2/EphB4 Signaling Pathway and Inhibits the Release of Proinflammatory Factors In Vivo.

Aseptic loosening caused by wear particles is one of the common complications after total hip arthroplasty. We investigated the effect of the recombinant protein ephB4-Fc (erythropoietin-producing human hepatocellular receptor 4) on wear particle-mediated inflammatory response. In vitro, ephrinB2 expression was analyzed using siRNA-NFATc1 (nuclear factor of activated T-cells 1) and siRNA-c-Fos. Additionally, we used Tartrate-resistant acid phosphatase (TRAP) staining, bone pit resorption, Enzyme-linked immunosorbent assay (ELISA), as well as ephrinB2 overexpression and knockdown experiments to verify the effect of ephB4-Fc on osteoclast differentiation and function. In vivo, a mouse skull model was constructed to test whether the ephB4-Fc inhibits osteolysis and inhibits inflammation by micro-CT, H&E staining, immunohistochemistry, and immunofluorescence. The gene expression of ephrinB2 was regulated by c-Fos/NFATc1. Titanium wear particles activated this signaling pathway to the promoted expression of the ephrinB2 gene. However, ephrinB2 protein can be activated by osteoblast membrane receptor ephB4 to inhibit osteoclast differentiation. In in vivo experiments, we found that ephB4 could regulate Ti particle-mediated imbalance of OPG/RANKL, and the most important finding was that ephB4 relieved the release of proinflammatory factors. The ephB4-Fc inhibits wear particle-mediated osteolysis and inflammatory response through the ephrinB2/EphB4 bidirectional signaling pathway, and ephrinB2 ligand is expected to become a new clinical drug therapeutic target.

A population-based propensity-matched study of regional dissections in patients with metastatic osteosarcoma.

BACKGROUND: The survival rates of patients with metastatic osteosarcoma are poor, and the prognosis is closely related to the choice of treatment, especially surgery. This study aimed to evaluate the survival outcomes of patients with metastatic osteosarcoma undergoing regional dissections. METHODS: We collected data on patients with metastatic osteosarcoma between 2004 and 2014 from the Surveillance, Epidemiology, and End Results (SEER) database. Kaplan-Meier curves were used to compare overall survival (OS) and cancer-specific survival (CSS), while univariate and multivariate Cox regression analyses were used to evaluate outcomes. Propensity score matching (PSM) was used to minimize the effects of confounding factors. RESULTS: The SEER database had records of 2768 patients diagnosed with osteosarcoma, of whom 398 were included in our study. Of the included patients, 116 (29.15%) underwent regional dissections, while 282 (70.85%) underwent non-regional dissections. The univariate and multivariate Cox regression analyses, prior to PSM, showed that OS (hazard ratio (HR): 0.34, 95% confidence interval (CI): 0.26-0.44, P<0.001 and HR: 0.47, 95% CI: 0.35-0.64, P<0.001, respectively) and CSS (HR: 0.33, 95% CI: 0.25-0.43, P<0.001 and HR: 0.46, 95% CI: 0.34-0.63, P<0.001, respectively) were better in patients who underwent regional dissections than those who underwent non-regional dissections. Compared with non-regional dissections, regional dissections, which included both primary tumour resection (PTR) and primary tumour and metastatic site resection (PTMR), were associated with better OS (P<0.001) and CSS (P<0.001) . However, the survival outcomes following PTR and PTMR showed no significant difference. After PSM, patients in the regional dissection group still had a higher OS (P<0.001) and CSS (P<0.001) than those in the non-regional dissection group. CONCLUSIONS: Compared with non-regional dissection, regional dissection resulted in better survival in patients with metastatic osteosarcoma.

Quercetin inhibits macrophage polarization through the p-38α/ß signalling pathway and regulates OPG/RANKL balance in a mouse skull model.

Aseptic loosening caused by wear particles is a common complication after total hip arthroplasty. We investigated the effect of the quercetin on wear particle-mediated macrophage polarization, inflammatory response and osteolysis. In vitro, we verified that Ti particles promoted the differentiation of RAW264.7 cells into M1 macrophages through p-38α/ß signalling pathway by using flow cytometry, immunofluorescence assay and small interfering p-38α/ß RNA. We used enzyme-linked immunosorbent assays to confirm that the protein expression of M1 macrophages increased in the presence of Ti particles and that these pro-inflammatory factors further regulated the imbalance of OPG/RANKL and promoted the differentiation of osteoclasts. However, this could be suppressed, and the protein expression of M2 macrophages was increased by the presence of the quercetin. In vivo, we revealed similar results in the mouse skull by µ-CT, H&E staining, immunohistochemistry and immunofluorescence assay. We obtained samples from patients with osteolytic tissue. Immunofluorescence analysis indicated that most of the macrophages surrounding the wear particles were M1 macrophages and that pro-inflammatory factors were released. Titanium particle-mediated M1 macrophage polarization, which caused the release of pro-inflammatory factors through the p-38α/ß signalling pathway, regulated OPG/RANKL balance. Macrophage polarization is expected to become a new clinical drug therapeutic target.

Pictilisib Enhances the Antitumor Effect of Doxorubicin and Prevents Tumor-Mediated Bone Destruction by Blockade of PI3K/AKT Pathway.

Despite advances in neoadjuvant chemotherapy, outcomes for patients with osteosarcoma resistant to first-line chemotherapy have been dismal for decades. There is thus an urgent need to develop novel targeted drugs to effectively treat refractory osteosarcoma. Dysregulation in the PI3K/AKT pathway has been observed during the development of osteosarcoma. Herein, we first evaluated p-AKT (Ser473) expression levels in osteosarcoma tissue using high-throughput tissue microarrays. Then, we demonstrated the role of pictilisib, a novel potent PI3K inhibitor, in osteosarcoma and related osteolysis. Functional studies of pictilisib in osteosarcoma cell lines and bone marrow-derived macrophages were performed in vitro. Patient-derived xenografts and orthotopic mouse models were used to assess the effects of pictilisib in vivo. The results showed that positive p-AKT expression levels after neoadjuvant chemotherapy were significantly associated with tumor cell necrosis rate. Pictilisib effectively inhibited the proliferation of osteosarcoma through G0/G1-S phase cell cycle arrest, and enhanced the sensitivity of osteosarcoma to doxorubicin, although it failed to induce cell apoptosis alone. In addition, pictilisib inhibited differentiation of osteoclasts and bone resorption in vitro and tumor-related osteolysis in vivo via inhibition of the PI3K/AKT/GSK3ß and NF-κB pathways. Pictilisib combined with conventional chemotherapy drugs represents a potential treatment strategy to suppress tumor growth and bone destruction in p-AKT-positive patients.

Recurrent SMARCB1 Mutations Reveal a Nucleosome Acidic Patch Interaction Site That Potentiates mSWI/SNF Complex Chromatin Remodeling.

Mammalian switch/sucrose non-fermentable (mSWI/SNF) complexes are multi-component machines that remodel chromatin architecture. Dissection of the subunit- and domain-specific contributions to complex activities is needed to advance mechanistic understanding. Here, we examine the molecular, structural, and genome-wide regulatory consequences of recurrent, single-residue mutations in the putative coiled-coil C-terminal domain (CTD) of the SMARCB1 (BAF47) subunit, which cause the intellectual disability disorder Coffin-Siris syndrome (CSS), and are recurrently found in cancers. We find that the SMARCB1 CTD contains a basic α helix that binds directly to the nucleosome acidic patch and that all CSS-associated mutations disrupt this binding. Furthermore, these mutations abrogate mSWI/SNF-mediated nucleosome remodeling activity and enhancer DNA accessibility without changes in genome-wide complex localization. Finally, heterozygous CSS-associated SMARCB1 mutations result in dominant gene regulatory and morphologic changes during iPSC-neuronal differentiation. These studies unmask an evolutionarily conserved structural role for the SMARCB1 CTD that is perturbed in human disease.