Experimental Study on Liquid Metal Embrittlement of Al-Zn-Mg Aluminum Alloy (7075): From Macromechanical Property Experiment to Microscopic Characterization.

This study is a multiscale experimental investigation into the embrittlement of Al-Zn-Mg aluminum alloy (7075-T6) caused by liquid metal gallium. The results of the experiment demonstrate that the tensile strength of the 7075-T6 aluminum alloy significantly weakens with an increase in the embrittlement temperature and a prolonged embrittlement time, whereas it improves with an increase in the strain rate. On the basis of the analysis of the experimental data, the sensitivity of the embrittlement of 7075-T6 aluminum alloy by liquid gallium to the loading strain rate is significantly higher compared to other environmental factors. In addition, this study also includes several experiments for microscopic observation, such as Scanning Electron Microscope (SEM) observation, Energy-Dispersive Spectrometer (EDS) spectroscopy, and Electron Back Scatter Diffraction (EBSD) analysis. The experimental observations confirmed the following: (1) gallium is enriched in the intergranular space of aluminum; (2) the fracture mode of 7075-T6 aluminum alloy changes from ductile to brittle fracture; and (3) the infiltration of liquid gallium into aluminum alloys and its enrichment in the intergranular space result in the formation of new dislocation nucleation sites, in addition to the original dislocations cutting and entanglement. This reduces the material's ability to undergo plastic deformation, intensifies stress concentration at the dislocation nucleation point, and, ultimately, leads to the evolution of dislocations into cracks.

Defining T cell receptor repertoires using nanovial-based binding and functional screening.

The ability to selectively bind to antigenic peptides and secrete effector molecules can define rare and low-affinity populations of cells with therapeutic potential in emerging T cell receptor (TCR) immunotherapies. We leverage cavity-containing hydrogel microparticles, called nanovials, each coated with peptide-major histocompatibility complex (pMHC) monomers to isolate antigen-reactive T cells. T cells are captured and activated by pMHCs inducing the secretion of effector molecules including IFN-γ and granzyme B that are accumulated on nanovials, allowing sorting based on both binding and function. The TCRs of sorted cells on nanovials are sequenced, recovering paired αß-chains using microfluidic emulsion-based single-cell sequencing. By labeling nanovials having different pMHCs with unique oligonucleotide-barcodes and secretions with oligo-barcoded detection antibodies, we could accurately link TCR sequences to specific targets and rank each TCR based on the corresponding cell's secretion level. Using the technique, we identified an expanded repertoire of functional TCRs targeting viral antigens with high specificity and found rare TCRs with activity against cancer-specific splicing-enhanced epitopes.

TERT mediates the U-shape of glucocorticoids effects in modulation of hippocampal neural stem cells and associated brain function.

BACKGROUND: Glucocorticoids (GCs) are steroidal hormones produced by the adrenal cortex. A physiological-level GCs have a crucial function in maintaining many cognitive processes, like cognition, memory, and mood, however, both insufficient and excessive GCs impair these functions. Although this phenomenon could be explained by the U-shape of GC effects, the underlying mechanisms are still not clear. Therefore, understanding the underlying mechanisms of GCs may provide insight into the treatments for cognitive and mood-related disorders. METHODS: Consecutive administration of corticosterone (CORT, 10 mg/kg, i.g.) proceeded for 28 days to mimic excessive GCs condition. Adrenalectomy (ADX) surgery was performed to ablate endogenous GCs in mice. Microinjection of 1 µL of Ad-mTERT-GFP virus into mouse hippocampus dentate gyrus (DG) and behavioral alterations in mice were observed 4 weeks later. RESULTS: Different concentrations of GCs were shown to affect the cell growth and development of neural stem cells (NSCs) in a U-shaped manner. The physiological level of GCs (0.01 µM) promoted NSC proliferation in vitro, while the stress level of GCs (10 µM) inhibited it. The glucocorticoid synthesis blocker metyrapone (100 mg/kg, i.p.) and ADX surgery both decreased the quantity and morphological development of doublecortin (DCX)-positive immature cells in the DG. The physiological level of GCs activated mineralocorticoid receptor and then promoted the production of telomerase reverse transcriptase (TERT); in contrast, the stress level of GCs activated glucocorticoid receptor and then reduced the expression of TERT. Overexpression of TERT by AD-mTERT-GFP reversed both chronic stresses- and ADX-induced deficiency of TERT and the proliferation and development of NSCs, chronic stresses-associated depressive symptoms, and ADX-associated learning and memory impairment. CONCLUSION: The bidirectional regulation of TERT by different GCs concentrations is a key mechanism mediating the U-shape of GC effects in modulation of hippocampal NSCs and associated brain function. Replenishment of TERT could be a common treatment strategy for GC dysfunction-associated diseases.

Structures and organizations of PSI-AcpPCI supercomplexes from red tidal and coral symbiotic photosynthetic dinoflagellates.

Marine photosynthetic dinoflagellates are a group of successful phytoplankton that can form red tides in the ocean and also symbiosis with corals. These features are closely related to the photosynthetic properties of dinoflagellates. We report here three structures of photosystem I (PSI)-chlorophylls (Chls) a/c-peridinin protein complex (PSI-AcpPCI) from two species of dinoflagellates by single-particle cryoelectron microscopy. The crucial PsaA/B subunits of a red tidal dinoflagellate Amphidinium carterae are remarkably smaller and hence losing over 20 pigment-binding sites, whereas its PsaD/F/I/J/L/M/R subunits are larger and coordinate some additional pigment sites compared to other eukaryotic photosynthetic organisms, which may compensate for the smaller PsaA/B subunits. Similar modifications are observed in a coral symbiotic dinoflagellate Symbiodinium species, where two additional core proteins and fewer AcpPCIs are identified in the PSI-AcpPCI supercomplex. The antenna proteins AcpPCIs in dinoflagellates developed some loops and pigment sites as a result to accommodate the changed PSI core, therefore the structures of PSI-AcpPCI supercomplex of dinoflagellates reveal an unusual protein assembly pattern. A huge pigment network comprising Chls a and c and various carotenoids is revealed from the structural analysis, which provides the basis for our deeper understanding of the energy transfer and dissipation within the PSI-AcpPCI supercomplex, as well as the evolution of photosynthetic organisms.

Assessing national vector control micro-planning in Zambia using the 2021 malaria indicator survey.

BACKGROUND: In 2020, the Zambia National Malaria Elimination Centre targeted the distribution of long-lasting insecticidal nets (LLINs) and indoor-residual spraying (IRS) campaigns based on sub-district micro-planning, where specified geographical areas at the health facility catchment level were assigned to receive either LLINs or IRS. Using data from the 2021 Malaria Indicator Survey (MIS), the objectives of this analysis were to (1) assess how well the micro-planning was followed in distributing LLINs and IRS, (2) investigate factors that contributed to whether households received what was planned, and (3) investigate how overall coverage observed in the 2021 MIS compared to the 2018 MIS conducted prior to micro-planning. METHODS: Households' receipt of ≥ 1 LLIN, and/or IRS within the past 12 months in the 2021 MIS, was compared against the micro-planning area under which the households fell. GPS points for 3,550 households were overlayed onto digitized micro-planning maps in order to determine what micro-plan the households fell under, and thus whether they received their planned intervention. Mixed-effects regression models were conducted to investigate what factors affected whether these households: (1) received their planned intervention, and (2) received any intervention. Finally, coverage indicators between the 2021 and 2018 MIS were compared. RESULTS: Overall, 60.0% (95%CI 55.4, 64.4) of households under a micro-plan received their assigned intervention, with significantly higher coverage of the planned intervention in LLIN-assigned areas (75.7% [95%CI 69.5, 80.9]) compared to IRS-assigned areas (49.4% [95%CI: 44.4, 54.4]). Regression analysis indicated that households falling under the IRS micro-plan had significantly reduced odds of receiving their planned intervention (OR: 0.34 [95%CI 0.24, 0.48]), and significantly reduced odds of receiving any intervention (OR: 0.51 [95%CI 0.37, 0.72] ), compared to households under the LLIN micro-plan. Comparison between the 2021 and 2018 MIS indicated a 27% reduction in LLIN coverage nationally in 2021, while IRS coverage was similar. Additionally, between 2018 and 2021, there was a 13% increase in households that received neither intervention. CONCLUSIONS: This analysis shows that although the micro-planning strategy adopted in 2020 worked much better for LLIN-assigned areas compared to IRS-assigned areas, there was reduced overall vector control coverage in 2021 compared to 2018 before micro-planning.

Dual-inhibitory domain iCARs improve the efficiency of the AND-NOT gate CAR T strategy.

CAR (chimeric antigen receptor) T cell therapy has shown clinical success in treating hematological malignancies, but its treatment of solid tumors has been limited. One major challenge is on-target, off-tumor toxicity, where CAR T cells also damage normal tissues that express the targeted antigen. To reduce this detrimental side-effect, Boolean-logic gates like AND-NOT gates have utilized an inhibitory CAR (iCAR) to specifically curb CAR T cell activity at selected nonmalignant tissue sites. However, the strategy seems inefficient, requiring high levels of iCAR and its target antigen for inhibition. Using a TROP2-targeting iCAR with a single PD1 inhibitory domain to inhibit a CEACAM5-targeting CAR (CEACAR), we observed that the inefficiency was due to a kinetic delay in iCAR inhibition of cytotoxicity. To improve iCAR efficiency, we modified three features of the iCAR-the avidity, the affinity, and the intracellular signaling domains. Increasing the avidity but not the affinity of the iCAR led to significant reductions in the delay. iCARs containing twelve different inhibitory signaling domains were screened for improved inhibition, and three domains (BTLA, LAIR-1, and SIGLEC-9) each suppressed CAR T function but did not enhance inhibitory kinetics. When inhibitory domains of LAIR-1 or SIGLEC-9 were combined with PD-1 into a single dual-inhibitory domain iCAR (DiCARs) and tested with the CEACAR, inhibition efficiency improved as evidenced by a significant reduction in the inhibitory delay. These data indicate that a delicate balance between CAR and iCAR signaling strength and kinetics must be achieved to regulate AND-NOT gate CAR T cell selectivity.

Temporal evolution reveals bifurcated lineages in aggressive neuroendocrine small cell prostate cancer trans-differentiation.

Trans-differentiation from an adenocarcinoma to a small cell neuroendocrine state is associated with therapy resistance in multiple cancer types. To gain insight into the underlying molecular events of the trans-differentiation, we perform a multi-omics time course analysis of a pan-small cell neuroendocrine cancer model (termed PARCB), a forward genetic transformation using human prostate basal cells and identify a shared developmental, arc-like, and entropy-high trajectory among all transformation model replicates. Further mapping with single cell resolution reveals two distinct lineages defined by mutually exclusive expression of ASCL1 or ASCL2. Temporal regulation by groups of transcription factors across developmental stages reveals that cellular reprogramming precedes the induction of neuronal programs. TFAP4 and ASCL1/2 feedback are identified as potential regulators of ASCL1 and ASCL2 expression. Our study provides temporal transcriptional patterns and uncovers pan-tissue parallels between prostate and lung cancers, as well as connections to normal neuroendocrine cell states.

Temperature and emissivity measurement algorithm using a moving emissivity retardation spectral window method based on Lagrange mean value theorem.

The multi-spectral radiation method is a non-contact technique that can measure the temperature and emissivity of an object. However, its core problem lies in solving the underdetermined equation system. Existing numerical emissivity methods require prior knowledge of emissivity, while emissivity function methods need accurate initial conditions. These approaches are not suitable for measuring unknown targets' temperature and emissivity. This paper proposes a moving emissivity retardation spectral window method that does not require any prior knowledge or initial conditions. The proposed method defines the emissivity retardation interval based on the Lagrange mean value theorem to provide universal and high-precision constraint conditions for solving the aforementioned underdetermined equation system. Simulation experiments were conducted on four target models with different emissivity, which showed that, compared to the moving narrowband window method, this new, to the best of our knowldge, approach reduced average temperature calculation errors by 31.0% and average emissivity calculation errors by 30.7%. In blackbody experiments, the calculated temperature error is about 0.4 K, and the emissivity is about 0.993-0.999. The described method is expected to meet the practical measurement needs for a wide range of substances.

Macrophage-Associated Genes for Predicting Prognosis and the Tumor Microenvironment in Patients with Hepatocellular Carcinoma.

Background: Hepatocellular carcinoma (HCC) is a highly malignant tumor, which is difficult to treat and has a poor prognosis. Immunotherapy has been a hot topic in liver cancer treatment in recent years, and macrophages play an important role in liver cancer immunotherapy. In this paper, we will use bioinformatics to analyze the significance of macrophage-associated genes (Mags) in hepatocellular carcinoma. Our goal is to determine the impact of macrophage-related genes on the immunotherapy, prognosis, and tumor microenvironment of HCC patients. Methods: 343 HCC patients with complete survival data were selected from RNA sequencing data from the Cancer Genome Atlas Hepatocellular carcinoma (TCGA-LIHC) database. Using univariate Cox regression analysis and Lasso regression analysis to identify macrophage-related genetic markers for prognostic HCC and constructed risk scores. Kaplan-Meier survival analysis helped to determine the relationship between genetic markers and overall survival (OS). Kaplan-Meier analysis was used to compare OS in stratified high-risk and low-risk groups. Risk scores and other clinical features were included to develop a prognostic profile of HCC. The accuracy of the model was evaluated by the receiver operating curve and calibration curve, respectively. Results: A prognostic risk model consisting of 7 Mags was constructed to accurately predict OS in the TCGA cohort. In univariate and multivariate Cox regression analyses, risk scores were prognostic factors independent of other clinical factors. The prognostic histogram showed that risk score had a good prognostic effect on survival risk stratification. The expression of immunotherapy markers such as CTLA4 and TNFRSF9 was upregulated in high-risk patients, indicating an underlying immunotherapy response in these patients. Conclusion: Our study constructs a macrophage-associated genetic marker for predicting OS in HCC patients, which may help guide clinical immunotherapy.

Silk fibroin-gelatin photo-crosslinked 3D-bioprinted hydrogel with MOF-methylene blue nanoparticles for infected wound healing.

Photo-crosslinked hydrogel (PH) is an outstanding candidate for three-dimensional (3D) printing as a wound dressing because of its high efficiency in crosslinking and injectability. In this study, methylene blue (MB)-loaded UiO-66(Ce) nanoparticles (NPs) were synthesized to prevent drug self-aggregation and achieve the photodynamic therapy (PDT) effect for efficient antibacterial action. Then, a composite photocrosslinked silk fibroin (SF)/gelatin hydrogel loaded with MB@UiO-66(Ce) NPs (MB@UiO-66(Ce)/PH) was fabricated. The printability and the improvement of the mechanical properties of the hydrogel by the NPs were clarified. The hydrogel exhibited good biocompatibility and promoted the migration and proliferation of fibroblasts. With the PDT effect of MB@UiO-66(Ce) NPs, the hydrogel showed an excellent antibacterial effect, which became more pronounced as the concentration increased. In vivo study showed that the MB@UiO-66(Ce)/PH could fill the defects without gaps and accelerate the repair rate of full-thickness skin defects in mice. The MB@UiO-66(Ce)/PH with antibacterial properties and tissue healing-promoting ability provides a new strategy involving 3D bioprinting for preparing wound dressings.

IRIS: Discovery of cancer immunotherapy targets arising from pre-mRNA alternative splicing.

Alternative splicing (AS) is prevalent in cancer, generating an extensive but largely unexplored repertoire of novel immunotherapy targets. We describe Isoform peptides from RNA splicing for Immunotherapy target Screening (IRIS), a computational platform capable of discovering AS-derived tumor antigens (TAs) for T cell receptor (TCR) and chimeric antigen receptor T cell (CAR-T) therapies. IRIS leverages large-scale tumor and normal transcriptome data and incorporates multiple screening approaches to discover AS-derived TAs with tumor-associated or tumor-specific expression. In a proof-of-concept analysis integrating transcriptomics and immunopeptidomics data, we showed that hundreds of IRIS-predicted TCR targets are presented by human leukocyte antigen (HLA) molecules. We applied IRIS to RNA-seq data of neuroendocrine prostate cancer (NEPC). From 2,939 NEPC-associated AS events, IRIS predicted 1,651 epitopes from 808 events as potential TCR targets for two common HLA types (A*02:01 and A*03:01). A more stringent screening test prioritized 48 epitopes from 20 events with "neoantigen-like" NEPC-specific expression. Predicted epitopes are often encoded by microexons of ≤30 nucleotides. To validate the immunogenicity and T cell recognition of IRIS-predicted TCR epitopes, we performed in vitro T cell priming in combination with single-cell TCR sequencing. Seven TCRs transduced into human peripheral blood mononuclear cells (PBMCs) showed high activity against individual IRIS-predicted epitopes, providing strong evidence of isolated TCRs reactive to AS-derived peptides. One selected TCR showed efficient cytotoxicity against target cells expressing the target peptide. Our study illustrates the contribution of AS to the TA repertoire of cancer cells and demonstrates the utility of IRIS for discovering AS-derived TAs and expanding cancer immunotherapies.

IFNγ Transcribed by IRF1 in CD4+ Effector Memory T Cells Promotes Senescence-Associated Pulmonary Fibrosis.

Physiologically aged lungs are prone to senescence-associated pulmonary diseases (SAPD). This study aimed to determine the mechanism and subtype of aged T cells affecting alveolar type II epithelial (AT2) cells, which promote the pathogenesis of senescence-associated pulmonary fibrosis (SAPF). Cell proportions, the relationship between SAPD and T cells, and the aging- and senescence-associated secretory phenotype (SASP) of T cells between young and aged mice were analyzed using lung single-cell transcriptomics. SAPD was monitored by markers of AT2 cells and found to be induced by T cells. Furthermore, IFNγ signaling pathways were activated and cell senescence, SASP, and T cell activation were shown in aged lungs. Physiological aging led to pulmonary dysfunction and TGF-ß1/IL-11/MEK/ERK (TIME) signaling-mediated SAPF, which was induced by senescence and SASP of aged T cells. Especially, IFNγ was produced by the accumulated CD4+ effector memory T (TEM) cells in the aged lung. This study also found that physiological aging increased pulmonary CD4+ TEM cells, IFNγ was produced mainly by CD4+ TEM cells, and pulmonary cells had increased responsiveness to IFNγ signaling. Specific regulon activity was increased in T cell subclusters. IFNγ transcriptionally regulated by IRF1 in CD4+ TEM cells promoted the epithelial-to-mesenchymal transition by activating TIME signaling and cell senescence of AT2 cells with aging. Accumulated IRF1+CD4+ TEM produced IFNγ in lung with aging and anti-IRF1 primary antibody treatment inhibited the expression of IFNγ. Aging might drive T cell differentiation toward helper T cells with developmental trajectories and enhance cell interactions of pulmonary T cells with other surrounding cells. Thus, IFNγ transcribed by IRF1 in CD4+ effector memory T cells promotes SAPF. IFNγ produced by CD4+ TEM cells in physiologically aged lungs could be a therapeutic target for preventing SAPF.

An Aerial-Wall Robotic Insect That Can Land, Climb, and Take Off from Vertical Surfaces.

Insects that can perform flapping-wing flight, climb on a wall, and switch smoothly between the 2 locomotion regimes provide us with excellent biomimetic models. However, very few biomimetic robots can perform complex locomotion tasks that combine the 2 abilities of climbing and flying. Here, we describe an aerial-wall amphibious robot that is self-contained for flying and climbing, and that can seamlessly move between the air and wall. It adopts a flapping/rotor hybrid power layout, which realizes not only efficient and controllable flight in the air but also attachment to, and climbing on, the vertical wall through a synergistic combination of the aerodynamic negative pressure adsorption of the rotor power and a climbing mechanism with bionic adhesion performance. On the basis of the attachment mechanism of insect foot pads, the prepared biomimetic adhesive materials of the robot can be applied to various types of wall surfaces to achieve stable climbing. The longitudinal axis layout design of the rotor dynamics and control strategy realize a unique cross-domain movement during the flying-climbing transition, which has important implications in understanding the takeoff and landing of insects. Moreover, it enables the robot to cross the air-wall boundary in 0.4 s (landing), and cross the wall-air boundary in 0.7 s (taking off). The aerial-wall amphibious robot expands the working space of traditional flying and climbing robots, which can pave the way for future robots that can perform autonomous visual monitoring, human search and rescue, and tracking tasks in complex air-wall environments.

Cytogeography of Naturalized Solidago canadensis Populations in Europe.

Autopolyploidization has driven the successful invasion of Solidago canadensis in East Asia. However, it was believed that only diploid S. canadensis invaded Europe, whereas polyploids never did. Here, molecular identification, ploidy level, and morphological traits of ten S. canadensis populations collected in Europe were compared with previously identified S. canadensis populations from other continents and S. altissima populations. Furthermore, the ploidy-driven geographical differentiation pattern of S. canadensis in different continents was investigated. All ten European populations were identified as S. canadensis with five diploid and five hexaploid populations. Significant differences in morphological traits existed among diploids and polyploids (tetraploids and hexaploids), rather than between polyploids from different introduced ranges and between S. altissima and polyploidy S. canadensis. The invasive hexaploids and diploids had few differences in latitudinal distributions in Europe, which was similar to the native range but different from a distinct climate-niche differentiation in Asia. This may be attributed to the bigger difference in climate between Asia and Europe and North America. The morphological and molecular evidences proved the invasion of polyploid S. canadensis in Europe and suggest that S. altissima may be merged into a complex of S. canadensis species. Our study may be concluded that geographical and ecological niche differentiation of an invasive plant driven by ploidy depends on the degree of difference in the environmental factors between the introduced and native range, which provides new insight into the invasive mechanism.

Hyaluronic acid-g-lipoic acid granular gel for promoting diabetic wound healing.

Diabetic patients are prone to developing chronic inflammation after trauma and have persistent nonhealing wounds. Reactive oxygen species (ROS) and recurrent bacterial infections at the site of long-term wounds also further delay skin wound healing and tissue regeneration. In this study, a granular gel (which exhibits ROS scavenging and antibacterial properties) is fabricated based on hyaluronic acid-g-lipoic acid (HA-LA). Briefly, HA-LA is synthesized to fabricate HA-LA microgels, which are further assembled by Ag+ via its coordination effect with disulfide in dithiolane to form a granular gel. The extrudable bulk granular gel possesses a shear-thinning feature and is immediately restored to a solid state after extrusion, and this can be easily applied to the whole wound area. Therefore, the grafted LA not only allows for the construction of the granular gel but also removes excess ROS from the microenvironment. Additionally, the presence of Ag+ realizes the assembly of microgels and has antibacterial effects. In vivo experiments show that the HA-LA granular gel eliminates excessive ROS at the wound site and up-regulates the secretion of reparative growth factors, thus, accelerating common and diabetic wound healing significantly. Therefore, the ROS-scavenging granular gel that can be applied to the wound surface with chronic inflammation demonstrates strong clinical utility.

Inter-synergized neuroprotection of costunolide engineered bone marrow mesenchymal stem cells targeting system.

Treatment of stroke remains difficult due to the unsatisfactory or unlocalized delivery of small molecule- and cell-based therapeutics in injured brain tissues. This is particularly the case for costunolide (Cos), which is highly neuroprotective and anti-inflammatory but finds great difficulty in reaching the brain. Here, we present that Cos induces the differentiation of bone marrow mesenchymal stem cells (bMSCs) into glia-like cells (C-bMSCs) capable of secreting neurotrophic factors and homing to injured brain tissues. By taking advantage of the homing effect, Cos and C-bMSCs were simultaneously funneled into the damaged brain by: (i) preparing Cos micelles (Cos-M) through entrapping Cos into the amphiphilic copolymer mPEG-PLGA [poly(ethylene oxide) monomethyl ether-poly(lactide-co-glycolide)], and (ii) incorporating Cos-M into C-bMSCs to give an intravenously injectable cell-like composite termed Cos@C-bMSCs, which displayed the inter-synergized neuroprotective efficacy in the cerebral ischemia reperfusion (CIR) injured rats. As desired, in the injured brain area, Cos@C-bMSCs simultaneously released Cos and C-bMSCs (glia-like cells) to repair the injured brain and to secret neurotrophic factors such as nerve growth factor (NGF). In view of the availability and reliability of autologous MSCs, the proof-of-concept design, development, and in vivo efficacy of Cos@C-bMSCs signify a movement in our management of brain damages.

Bmi-1 Overexpression Improves Sarcopenia Induced by 1,25(OH)2 D3 Deficiency and Downregulates GATA4-Dependent Rela Transcription.

Sarcopenia increases with age, and an underlying mechanism needs to be determined to help with designing more effective treatments. This study aimed to determine whether 1,25(OH)2 D3 deficiency could cause cellular senescence and a senescence-associated secretory phenotype (SASP) in skeletal muscle cells to induce sarcopenia, whether GATA4 could be upregulated by 1,25(OH)2 D3 deficiency to promote SASP, and whether Bmi-1 reduces the expression of GATA4 and GATA4-dependent SASP induced by 1,25(OH)2 D3 deficiency in skeletal muscle cells. Bioinformatics analyses with RNA sequencing data in skeletal muscle from physiologically aged and young mice were conducted. Skeletal muscles from 2-month-old young and 2-year-old physiologically aged wild-type (WT) mice and 8-week-old WT, Bmi-1 mesenchymal transgene (Bmi-1Tg ), Cyp27b1 homozygous (Cyp27b1-/- ), and Bmi-1Tg Cyp27b1-/- mice were observed for grip strength, cell senescence, DNA damage, and NF-κB-mediated SASP signaling of skeletal muscle. We found that muscle-derived Bmi-1 and vitamin D receptor (VDR) decreased with physiological aging, and DNA damage and GATA4-dependent SASP activation led to sarcopenia. Furthermore, 1,25(OH)2 D3 deficiency promoted DNA damage-induced GATA4 accumulation in muscles. GATA4 upregulated Rela at the region from -1448 to -1412 bp at the transcriptional level to cause NF-κB-dependent SASP for aggravating cell senescence and muscular dysfunction and sarcopenia. Bmi-1 overexpression promoted the ubiquitination and degradation of GATA4 by binding RING1B, which prevented cell senescence, SASP, and dysfunctional muscle, and improved sarcopenia induced by 1,25(OH)2 D3 deficiency. Thus, Bmi-1 overexpression improves sarcopenia induced by 1,25(OH)2 D3 deficiency, downregulates GATA4-dependent Rela transcription, and sequentially inhibits GATA4-dependent SASP in muscle cells. Therefore, Bmi-1 overexpression could be used for translational gene therapy for the ubiquitination of GATA4 and prevention of sarcopenia. © 2023 American Society for Bone and Mineral Research (ASBMR).

Defining T cell receptor repertoires using nanovial-based affinity and functional screening.

The ability to selectively bind to antigenic peptides and secrete cytokines can define populations of cells with therapeutic potential in emerging T cell receptor (TCR) immunotherapies. We leverage cavity-containing hydrogel microparticles, called nanovials, each coated with millions of peptide-major histocompatibility complex (pMHC) monomers to isolate antigen-reactive T cells. T cells are captured and activated by pMHCs and secrete cytokines on nanovials, allowing sorting based on both affinity and function. The TCRs of sorted cells on nanovials are sequenced, recovering paired αß-chains using microfluidic emulsion-based single-cell sequencing. By labeling nanovials having different pMHCs with unique oligonucleotide-barcodes we could link TCR sequence to targets with 100% accuracy. We identified with high specificity an expanded repertoire of functional TCRs targeting viral antigens compared to standard techniques.

12-Epi-Napelline regulated TGF-ß/BMP signaling pathway mediated by BMSCs paracrine acceleration against osteoarthritis.

BACKGROUND: This study is to investigate the role of 12-Epi-Napelline, a new alkaloid isolated from aconitum, in promoting the paracrine of Bone Mesenchymal Stem Cells (BMSCs) and the synergistic therapeutic effects on osteoarthritis. METHOD: We tested the cytotoxicity and optimization of 12-Epi-Napelline, and then simulated the osteoarthritis model in vitro damaging the chondrocytes by lipopolysaccharide (LPS) and RT-qPCR, Western blot and Immunofluorescence were used to detect the inflammatory factor IL-1ß, COX-2, TNF-α, MMP-13 and anabolic cytokines of Col-2, BMP-2, TGF-ß1 and Sox9 expression in chondrocytes after 12-Epi-Napelline treatment. Under the treatment of different time, Col-2, BMP-2, TGF-ß1 and Sox9 expression in BMSCs were detected by RT-qPCR, Western blot, and Immunofluorescence. By establishing an osteoarthritis model in vivo, the anti-osteoarthritis effect of 12-Epi-Napelline or BMSCs was evaluated. RESULTS: The results showed the expressions of IL-1ß, COX-2, TNF-α, and MMP-13 were down-regulated in chondrocytes after 12-Epi-Napelline treatment, while the expression of Col-2, BMP-2, TGF-ß1 and Sox9 were increased to normal chondrocytes. These increased expression also occurred in BMSCs. BMSCs had the trend of transforming into chondrocytes by regulating TGF-ß signaling pathway under the treatment of 12-Epi-Napelline. CONCLUSION: This study could confirm that 12-Epi-Napelline is not only effective in the treatment of osteoarthritis, but also can induce BMSCs to secrete growth factors that promote chondrocyte repair to help repair the damage caused by osteoarthritis.