Brain tissue- and cell type-specific eQTL Mendelian randomization reveals efficacy of FADS1 and FADS2 on cognitive function

Epidemiological studies suggested an association between omega-3 fatty acids and cognitive function. However, the causal role of the fatty acid desaturase (FADS) gene, which play a key role in regulating omega-3 fatty acids biosynthesis, on cognitive function is unclear. Hence, we used two-sample Mendelian randomization (MR) to estimate the gene-specific causal effect of omega-3 fatty acids (N = 114,999) on cognitive function (N = 300,486). Tissue- and cell type-specific effects of FADS1/FADS2 expression on cognitive function were estimated using brain tissue cis-expression quantitative trait loci (cis-eQTL) datasets (GTEx, N ≤ 209; MetaBrain, N ≤ 8,613) and single cell cis-eQTL data (N = 373), respectively. These causal effects were further evaluated in whole blood cis-eQTL data (N ≤ 31,684). A series of sensitivity analyses were conducted to validate MR assumptions. Leave-one-out MR showed a FADS gene-specific effect of omega-3 fatty acids on cognitive function [β = -1.3 × 10-2, 95% confidence interval (CI) (-2.2 × 10-2, -5 × 10-3), P = 2 × 10-3]. Tissue-specific MR showed an effect of increased FADS1 expression in cerebellar hemisphere and FADS2 expression in nucleus accumbens basal ganglia on maintaining cognitive function, while decreased FADS1 expression in nine brain tissues on maintaining cognitive function [colocalization probability (PP.H4) ranged from 71.7% to 100.0%]. Cell type-specific MR showed decreased FADS1/FADS2 expression in oligodendrocyte was associated with maintaining cognitive function (PP.H4 = 82.3%, respectively). Increased FADS1/FADS2 expression in whole blood showed an effect on cognitive function maintenance (PP.H4 = 86.6% and 88.4%, respectively). This study revealed putative causal effect of FADS1/FADS2 expression in brain tissues and blood on cognitive function. These findings provided evidence to prioritize FADS gene as potential target gene for maintenance of cognitive function.

Prevalence and optical coherence tomography analyses of outer retinal tubulations in Chinese population with inherited retinal diseases

BACKGROUND

To investigate the prevalence of outer retinal tubulation (ORT) and its correlations with optical coherence tomography (OCT) parameters in Chinese population with inherited retinal diseases (IRDs).

METHODS

This retrospective study enrolled consecutive patients identified with IRDs and referred for genetic testing between February 2016 and April 2021. Clinical characteristics from medical records and features of cross-sectional B-scans were reviewed and analysed. The associations of patient-specific and ocular features with the presence of ORT were evaluated using univariate and multivariate analyses.

RESULTS

Two hundred and three patients (401 eyes) with a mean age of 49.7 ± 16.7 years were enrolled. ORT was observed in 41 eyes (10.2%), including 26 of 28 eyes (92.9%) with Bietti crystalline corneoretinal dystrophy (BCD), 14 of 338 eyes (4.1%) with retinitis pigmentosa (RP), and 1 of 26 eyes (3.8%) in eyes with cone-rod dystrophy. Eyes with ORT showed significantly worse visual acuity than those without ORT (P = 0.002). Multivariate analysis indicated that the presence of ORT was positively correlated with choroidal atrophy and inner nuclear layer (INL) cysts (P < 0.01). ORTs were detected more frequently in eyes with BCD than RP (P = 0.024), most of which located exclusively within the extrafoveal area. Large choroidal vessels were detected underneath the corresponding ORTs in both patients with BCD and RP.

CONCLUSIONS

The prevalence of ORT varies among different IRDs phenotypes, with the highest prevalence in BCD. The presence of choroidal atrophy and INL cysts may be associated with an increased risk of ORT formation in patients with IRD.

C-to-G editing generates double-strand breaks causing deletion, transversion and translocation

Base editors (BEs) introduce base substitutions without double-strand DNA cleavage. Besides precise substitutions, BEs generate low-frequency 'stochastic' byproducts through unclear mechanisms. Here, we performed in-depth outcome profiling and genetic dissection, revealing that C-to-G BEs (CGBEs) generate substantial amounts of intermediate double-strand breaks (DSBs), which are at the centre of several byproducts. Imperfect DSB end-joining leads to small deletions via end-resection, templated insertions or aberrant transversions during end fill-in. Chromosomal translocations were detected between the editing target and off-targets of Cas9/deaminase origin. Genetic screenings of DNA repair factors disclosed a central role of abasic site processing in DSB formation. Shielding of abasic sites by the suicide enzyme HMCES reduced CGBE-initiated DSBs, providing an effective way to minimize DSB-triggered events without affecting substitutions. This work demonstrates that CGBEs can initiate deleterious intermediate DSBs and therefore require careful consideration for therapeutic applications, and that HMCES-aided CGBEs hold promise as safer tools.

Asymmetric α-C(sp3)-H allylic alkylation of primary alkylamines by synergistic Ir/ketone catalysis

Primary alkyl amines are highly reactive in N-nucleophilic reactions with electrophiles. However, their α-C-H bonds are unreactive towards electrophiles due to their extremely low acidity (pKa ~57). Nonetheless, 1,8-diazafluoren-9-one (DFO) can activate primary alkyl amines by increasing the acidity of the α-amino C-H bonds by up to 1044 times. This makes the α-amino C-H bonds acidic enough to be deprotonated under mild conditions. By combining DFO with an iridium catalyst, direct asymmetric α-C-H alkylation of NH2-unprotected primary alkyl amines with allylic carbonates has been achieved. This reaction produces a wide range of chiral homoallylic amines with high enantiopurities. The approach has successfully switched the reactivity between primary alkyl amines and allylic carbonates from intrinsic allylic amination to the α-C-H alkylation, enabling the construction of pharmaceutically significant chiral homoallylic amines from readily available primary alkyl amines in a single step.

Collagen I-induced VCAN/ERK signaling and PARP1/ZEB1-mediated metastasis facilitate OSBPL2 defect to promote colorectal cancer progression

The global burden of colorectal cancer (CRC) has rapidly increased in recent years. Dysregulated cholesterol homeostasis facilitated by extracellular matrix (ECM) remodeling transforms the tumor microenvironment. Collagen I, a major with ECM component is highly expressed in colorectal tumors with infiltrative growth. Although oxysterol binding protein (OSBP)-related proteins accommodate tumorigenesis, OSBPL2, which is usually involved in deafness, is not associated with CRC progression. Therefore, we aimed to investigate the pathological function of OSBPL2 and identify the molecular link between ECM-Collagen I and OSBPL2 in CRC to facilitate the development of new treatments for CRC. OSBPL2 predicted a favorable prognosis in stage IV CRC and substantially repressed Collagen I-induced focal adhesion, migration, and invasion. The reduction of OSBPL2 activated ERK signaling through the VCAN/AREG/EREG axis during CRC growth, while relying on PARP1 via ZEB1 in CRC metastasis. OSBPL2 defect supported colorectal tumor growth and metastasis, which were suppressed by the ERK and PARP1 inhibitors SCH772984 and AG14361, respectively. Overall, our findings revealed that the Collagen I-induced loss of OSBPL2 aggravates CRC progression through VCAN-mediated ERK signaling and the PARP1/ZEB1 axis. This demonstrates that SCH772984 and AG14361 are reciprocally connective therapies for OSBPL2Low CRC, which could contribute to further development of targeted CRC treatment.

Giant tunnelling electroresistance in atomic-scale ferroelectric tunnel junctions

Ferroelectric tunnel junctions are promising towards high-reliability and low-power non-volatile memories and computing devices. Yet it is challenging to maintain a high tunnelling electroresistance when the ferroelectric layer is thinned down towards atomic scale because of the ferroelectric structural instability and large depolarization field. Here we report ferroelectric tunnel junctions based on samarium-substituted layered bismuth oxide, which can maintain tunnelling electroresistance of 7 × 105 with the samarium-substituted bismuth oxide film down to one nanometer, three orders of magnitude higher than previous reports with such thickness, owing to efficient barrier modulation by the large ferroelectric polarization. These ferroelectric tunnel junctions demonstrate up to 32 resistance states without any write-verify technique, high endurance (over 5 × 109), high linearity of conductance modulation, and long retention time (10 years). Furthermore, tunnelling electroresistance over 109 is achieved in ferroelectric tunnel junctions with 4.6-nanometer samarium-substituted bismuth oxide layer, which is higher than commercial flash memories. The results show high potential towards multi-level and reliable non-volatile memories.

ZBTB7B is a permissive regulator of hepatocellular carcinoma initiation by repressing c-Jun expression and function

Hepatocarcinogenesis is a multi-step process. However, the regulators of hepatocellular carcinoma (HCC) initiation are understudied. Adult liver-specific gene expression was globally downregulated in HCC. We hypothesize that adult liver-specific genes, especially adult liver-enriched transcription factors may exert tumor-suppressive functions in HCC. In this study, we identify ZBTB7B, an adult liver-enriched transcription factor as a permissive regulator of HCC initiation. ZBTB7B is highly expressed in hepatocytes in adult livers, compared to fetal livers. To evaluate the functions of ZBTB7B in hepatocarcinogenesis, we performed hepatocyte-specific ZBTB7B knockout in hydrodynamic oncogene transfer-induced mouse liver cancer models. Hepatocyte-specific knockout of ZBTB7B promotes activated Akt and N-Ras-induced HCC development. Moreover, ZBTB7B deficiency sensitizes hepatocytes to a single oncogene Akt-induced oncogenic transformation and HCC initiation, which is otherwise incompetent in inducing HCC. ZBTB7B deficiency accelerates HCC initiation by down-regulating adult liver-specific gene expression and priming livers to a fetal-like state. The molecular mechanism underlying ZBTB7B functions in hepatocytes was investigated by integrated transcriptomic, phosphoproteomic, and chromatin immunoprecipitation-sequencing analyses. Integrative multi-omics analyses identify c-Jun as the core signaling node in ZBTB7B-deficient liver cancer initiation. c-Jun is a direct target of ZBTB7B essential to accelerated liver cancer initiation in ZBTB7B-deficient livers. Knockdown of c-Jun expression or dominant negative c-Jun expression delays HCC development in ZBTB7B-deficient livers. In addition, ZBTB7B competes with c-Jun for chromatin binding. Ectopic ZBTB7B expression attenuates the tumor-promoting functions of c-Jun. Expression of ZBTB7B signature, composed of 140 genes co-regulated by ZBTB7B and c-Jun, is significantly downregulated in early-stage HCCs compared to adjacent normal tissues, correlates to liver-specific gene expression, and is associated with good prognosis in human HCC. Thus, ZBTB7B functions as a permissive regulator of HCC initiation by directly regulating c-Jun expression and function.

Biomimetic Bouligand chiral fibers array enables strong and superelastic ceramic aerogels

Ceramic aerogels are often used when thermal insulation materials are desired; however, they are still plagued by poor mechanical stability under thermal shock. Here, inspired by the dactyl clubs of mantis shrimp found in nature, which form by directed assembly into hierarchical, chiral and Bouligand (twisted plywood) structure exhibiting superior mechanical properties, we present a compositional and structural engineering strategy to develop strong, superelastic and fatigue resistance ceramic aerogels with chiral fibers array resembling Bouligand architecture. Benefiting from the stress dissipation, crack torsion and mechanical reinforcement of micro-/nano-scale Bouligand array, the tensile strength of these aerogels (170.38 MPa) is between one and two orders of magnitude greater than that of state-of-the-art nanofibrous aerogels. In addition, the developed aerogels feature low density and thermal conductivity, good compressive properties with rapid recovery from 80 % strain, and thermal stability up to 1200 °C, making them ideal for thermal insulation applications.

A biphenotypic lymphocyte subset displays both T- and B-cell functionalities

T cell/B cell mixed phenotypic lymphocytes have been observed in different disease contexts, yet their presence and function in physiological conditions remain elusive. Here, we provide evidence for the existence of a lymphocyte subset endogenously expressing both T- and B-cell lineage markers in mice. The majority of these T/B phenotypic lymphocytes (CD3+CD19+) show an origin of pro/pre B cells and distribute widely in mouse bone marrow, lymph nodes, spleen, and peripheral blood. Functional assays show that these biphenotypic lymphocytes can be activated through stimulating TCR or BCR signaling pathways. Moreover, we show that these cells actively participate both the humoral and cellular immune responses elicited by vaccination. Compared to conventional T cells, these biphenotypic lymphocytes can secrete a higher level of IL-2 but a lower level of TNF-α upon antigen specific stimulation. An equivalent lymphocyte subset is found in freshly isolated human PBMCs and exhibits similar functionality, albeit at a lower frequency than in mice.

NDP52 mediates an antiviral response to hepatitis B virus infection through Rab9-dependent lysosomal degradation pathway

Autophagy receptor NDP52 triggers bacterial autophagy against infection. However, the ability of NDP52 to protect against viral infection has not been established. We show that NDP52 binds to envelope proteins of hepatitis B virus (HBV) and triggers a degradation process that promotes HBV clearance. Inactivating NDP52 in hepatocytes results in decreased targeting of viral envelopes in the lysosome and increased levels of viral replication. NDP52 inhibits HBV at both viral entry and late replication stages. In contrast to NDP52-mediated bacterial autophagy, lysosomal degradation of HBV envelopes is independent of galectin 8 and ATG5. NDP52 forms complex with Rab9 and viral envelope proteins and links HBV to Rab9-dependent lysosomal degradation pathway. These findings reveal that NDP52 acts as a sensor for HBV infection, which mediates a unique antiviral response to eliminate the virus. This work also suggests direct roles for autophagy receptors in other lysosomal degradation pathways than canonical autophagy.

Type I collagen and fibromodulin enhance the tenogenic phenotype of hASCs and their potential for tendon regeneration

Our previous work demonstrated the tendon-derived extracellular matrix (ECM) extracts as vital niches to specifically direct mesenchymal stem cells towards tenogenic differentiation. This study aims to further define the effective ECM molecules capable of teno-lineage induction on human adipose-derived stem cells (hASCs) and test their function for tendon engineering. By detecting the teno-markers expression levels in hASCs exposed to various substrate coatings, collagen I (COL1) and fibromodulin (FMOD) were identified to be the key molecules as a combination and further employed to the modification of poly(L-lactide-co-ε-caprolactone) electrospun nanoyarns, which showed advantages in inducting seeded hASCs for teno-lineage specific differentiation. Under dynamic mechanical loading, modified scaffold seeded with hASCs formed neo-tendon in vitro at the histological level and formed better tendon tissue in vivo with mature histology and enhanced mechanical properties. Primary mechanistic investigation with RNA sequencing demonstrated that the inductive mechanism of these two molecules for hASCs tenogenic differentiation was directly correlated with positive regulation of peptidase activity, regulation of cell-substrate adhesion and regulation of cytoskeletal organization. These biological processes were potentially affected by LOC101929398/has-miR-197-3p/TENM4 ceRNA regulation axis. In summary, COL1 and FMOD in combination are the major bioactive molecules in tendon ECM for likely directing tenogenic phenotype of hASCs and certainly valuable for hASCs-based tendon engineering.

Elevated peripheral levels of receptor-interacting protein kinase 1 (RIPK1) and IL-8 as biomarkers of human amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a devastating fatal neurodegenerative disease with no cure. Receptor-interacting protein kinase 1 (RIPK1) has been proposed to mediate pathogenesis of ALS. Primidone has been identified as an old drug that can also inhibit RIPK1 kinase. We conducted a drug-repurposing biomarker study of primidone as a RIPK1 inhibitor using SOD1G93A mice and ALS patients. SOD1G93A mice treated with primidone showed significant delay of symptomatic onset and improved motor performance. One-hundred-sixty-two ALS participants dosed daily with primidone (62.5 mg) completed 24-week follow-up. A significant reduction was showed in serum levels of RIPK1 and IL-8, which were significantly higher in ALS patients than that of healthy controls (P < 0.0001). Serum RIPK1 levels were correlated positively with the severity of bulbar symptoms (P < 0.05). Our study suggests that serum levels of RIPK1 and IL-8 in peripheral can be used as clinical biomarkers for the activation of RIPK1 in central nervous system in human ALS patients. Repurposing primidone may provide a promising therapeutic strategy for ALS. The effect of primidone for the treatment of other inflammatory diseases may also be considered, since the activation of RIPK1 has been implicated in mediating a variety of inflammatory diseases including COVID-19-associated cytokine release syndrome (CRS). (ChiCTR2200060149).

A deep unrolled neural network for real-time MRI-guided brain intervention

Accurate navigation and targeting are critical for neurological interventions including biopsy and deep brain stimulation. Real-time image guidance further improves surgical planning and MRI is ideally suited for both pre- and intra-operative imaging. However, balancing spatial and temporal resolution is a major challenge for real-time interventional MRI (i-MRI). Here, we proposed a deep unrolled neural network, dubbed as LSFP-Net, for real-time i-MRI reconstruction. By integrating LSFP-Net and a custom-designed, MR-compatible interventional device into a 3 T MRI scanner, a real-time MRI-guided brain intervention system is proposed. The performance of the system was evaluated using phantom and cadaver studies. 2D/3D real-time i-MRI was achieved with temporal resolutions of 80/732.8 ms, latencies of 0.4/3.66 s including data communication, processing and reconstruction time, and in-plane spatial resolution of 1 × 1 mm2. The results demonstrated that the proposed method enables real-time monitoring of the remote-controlled brain intervention, and showed the potential to be readily integrated into diagnostic scanners for image-guided neurosurgery.

In vivo RNA interactome profiling reveals 3'UTR-processed small RNA targeting a central regulatory hub

Small noncoding RNAs (sRNAs) are crucial regulators of gene expression in bacteria. Acting in concert with major RNA chaperones such as Hfq or ProQ, sRNAs base-pair with multiple target mRNAs and form large RNA-RNA interaction networks. To systematically investigate the RNA-RNA interactome in living cells, we have developed a streamlined in vivo approach iRIL-seq (intracellular RIL-seq). This generic approach is highly robust, illustrating the dynamic sRNA interactomes in Salmonella enterica across multiple stages of growth. We have identified the OmpD porin mRNA as a central regulatory hub that is targeted by a dozen sRNAs, including FadZ cleaved from the conserved 3'UTR of fadBA mRNA. Both ompD and FadZ are activated by CRP, constituting a type I incoherent feed-forward loop in the fatty acid metabolism pathway. Altogether, we have established an approach to profile RNA-RNA interactomes in live cells, highlighting the complexity of RNA regulatory hubs and RNA networks.

Dissecting neural computations in the human auditory pathway using deep neural networks for speech

The human auditory system extracts rich linguistic abstractions from speech signals. Traditional approaches to understanding this complex process have used linear feature-encoding models, with limited success. Artificial neural networks excel in speech recognition tasks and offer promising computational models of speech processing. We used speech representations in state-of-the-art deep neural network (DNN) models to investigate neural coding from the auditory nerve to the speech cortex. Representations in hierarchical layers of the DNN correlated well with the neural activity throughout the ascending auditory system. Unsupervised speech models performed at least as well as other purely supervised or fine-tuned models. Deeper DNN layers were better correlated with the neural activity in the higher-order auditory cortex, with computations aligned with phonemic and syllabic structures in speech. Accordingly, DNN models trained on either English or Mandarin predicted cortical responses in native speakers of each language. These results reveal convergence between DNN model representations and the biological auditory pathway, offering new approaches for modeling neural coding in the auditory cortex.

Structure-based discovery of dual pathway inhibitors for SARS-CoV-2 entry

Since 2019, SARS-CoV-2 has evolved rapidly and gained resistance to multiple therapeutics targeting the virus. Development of host-directed antivirals offers broad-spectrum intervention against different variants of concern. Host proteases, TMPRSS2 and CTSL/CTSB cleave the SARS-CoV-2 spike to play a crucial role in the two alternative pathways of viral entry and are characterized as promising pharmacological targets. Here, we identify compounds that show potent inhibition of these proteases and determine their complex structures with their respective targets. Furthermore, we show that applying inhibitors simultaneously that block both entry pathways has a synergistic antiviral effect. Notably, we devise a bispecific compound, 212-148, exhibiting the dual-inhibition ability of both TMPRSS2 and CTSL/CTSB, and demonstrate antiviral activity against various SARS-CoV-2 variants with different viral entry profiles. Our findings offer an alternative approach for the discovery of SARS-CoV-2 antivirals, as well as application for broad-spectrum treatment of viral pathogenic infections with similar entry pathways.

Enhanced copper anticorrosion from Janus-doped bilayer graphene

The atomic-thick anticorrosion coating for copper (Cu) electrodes is essential for the miniaturisation in the semiconductor industry. Graphene has long been expected to be the ultimate anticorrosion material, however, its real anticorrosion performance is still under great controversy. Specifically, strong electronic couplings can limit the interfacial diffusion of corrosive molecules, whereas they can also promote the surficial galvanic corrosion. Here, we report the enhanced anticorrosion for Cu simply via a bilayer graphene coating, which provides protection for more than 5 years at room temperature and 1000 h at 200 °C. Such excellent anticorrosion is attributed to a nontrivial Janus-doping effect in bilayer graphene, where the heavily doped bottom layer forms a strong interaction with Cu to limit the interfacial diffusion, while the nearly charge neutral top layer behaves inertly to alleviate the galvanic corrosion. Our study will likely expand the application scenarios of Cu under various extreme operating conditions.

Data-driven discovery of electrocatalysts for CO2 reduction using active motifs-based machine learning

The electrochemical carbon dioxide reduction reaction (CO2RR) is an attractive approach for mitigating CO2 emissions and generating value-added products. Consequently, discovery of promising CO2RR catalysts has become a crucial task, and machine learning (ML) has been utilized to accelerate catalyst discovery. However, current ML approaches are limited to exploring narrow chemical spaces and provide only fragmentary catalytic activity, even though CO2RR produces various chemicals. Here, by merging pre-developed ML model and a CO2RR selectivity map, we establish high-throughput virtual screening strategy to suggest active and selective catalysts for CO2RR without being limited to a database. Further, this strategy can provide guidance on stoichiometry and morphology of the catalyst to researchers. We predict the activity and selectivity of 465 metallic catalysts toward four expected reaction products. During this process, we discover previously unreported and promising behavior of Cu-Ga and Cu-Pd alloys. These findings are then validated through experimental methods.

Microfluidic magnetic detection system combined with a DNA framework-mediated immune-sandwich assay for rapid and sensitive detection of tumor-derived exosomes

Tumor-derived circulating exosomes (TDEs) are being pursued as informative and noninvasive biomarkers. However, quantitatively detecting TDEs is still challenging. Herein, we constructed a DNA tetrahedral-structured probe (TSP)-mediated microfluidic magnetic detection system (μFMS) to provide a rapid and sensitive platform for analyzing TDEs. CD63 aptamer-modified Fe3O4 magnetic nanoparticles (MNPs) were constructed to form magnetic nano-report probes (MNRs). The microfluidic chips were fabricated from glass functionalized with DNA TSP-modified aldehyde groups and a PDMS layer designed with serpentine microchannels. An induction coil-based magnetic detector was used to measure the magnetic signal. The linear dynamic range of the μFMS system for TDE assays was 1.98 × 103-1.98 × 107 particles/mL with a limit of detection of 1.98 × 103 particles/mL in PBS. There was no significant difference in TDE detection between the simulated serum and PBS, which indicated the feasibility of the constructed μFMS system for TDE analysis in complex biological systems. In terms of cost, reaction time and operation procedure, this μFMS has the potential to be developed as a clinical point-of-care testing tool for cancer diagnosis and therapeutics.

Design and application of the transformer base editor in mammalian cells and mice

Fusing apolipoprotein B mRNA-editing enzyme, catalytic polypeptide-like cytidine deaminase with catalytically impaired Cas proteins (e.g., nCas9 or dCas9) provides a novel gene-editing technology, base editing, that grants targeted base substitutions with high efficiency. However, genome-wide and transcriptome-wide off-target mutations are observed in base editing, which raises safety concerns regarding therapeutic applications. Previously, we developed a new base editing system, the transformer base editor (tBE), to induce efficient editing with no observable genome-wide or transcriptome-wide off-target mutations both in mammalian cells and in mice. Here we describe a detailed protocol for the design and application of the tBE. Steps for designing single-guide RNA (sgRNA) and helper sgRNA pairs, making constructs, determining the genome-wide and transcriptome-wide off-target mutations, producing the tBE-containing adeno-associated viruses, delivering adeno-associated viruses into mice and examining the in vivo editing effects are included in this protocol. High-precision base editing by the tBE can be completed within 2-3 weeks (in mammalian cells) or within 6-8 weeks (in mice), with sgRNA-helper sgRNA pairs. The whole process can be collaboratively accomplished by researchers using standard techniques from molecular biology, bioinformatics and mouse husbandry.

FBXO38 regulates macrophage polarization to control the development of cancer and colitis

Macrophages are highly plastic cells that differentially regulate multiple pathological conditions, including cancer and autoimmune diseases. In response to various stimuli, macrophages activate different intrinsic signaling pathways and polarize into distinct macrophage subsets. We aimed to identify key new effectors that could control macrophage polarization and impact the development of cancer or colitis. Following treatment with the supernatants of tumor cells, macrophages showed an upregulation in Fbxo38 expression. Subsequently, we further identified that FBXO38 promotes macrophage immunosuppressive function by upregulating the expression of M2-like genes via MAPK and IRF4 signaling without affecting M1-like macrophage polarization. Deletion of Fbxo38 in macrophages was found to block tumor development and protect against DSS-induced colitis. Considering the distinct regulation of tumor development by FBXO38 in T cells and macrophages, we suggest that a comprehensive understanding of FBXO38 function in different cell types is critical for its further translational usage.

Revealing the signaling of complement receptors C3aR and C5aR1 by anaphylatoxins

The complement receptors C3aR and C5aR1, whose signaling is selectively activated by anaphylatoxins C3a and C5a, are important regulators of both innate and adaptive immune responses. Dysregulations of C3aR and C5aR1 signaling lead to multiple inflammatory disorders, including sepsis, asthma and acute respiratory distress syndrome. The mechanism underlying endogenous anaphylatoxin recognition and activation of C3aR and C5aR1 remains elusive. Here we reported the structures of C3a-bound C3aR and C5a-bound C5aR1 as well as an apo-C3aR structure. These structures, combined with mutagenesis analysis, reveal a conserved recognition pattern of anaphylatoxins to the complement receptors that is different from chemokine receptors, unique pocket topologies of C3aR and C5aR1 that mediate ligand selectivity, and a common mechanism of receptor activation. These results provide crucial insights into the molecular understanding of C3aR and C5aR1 signaling and structural templates for rational drug design for treating inflammation disorders.

Wafer-scale organic-on-III-V monolithic heterogeneous integration for active-matrix micro-LED displays

The organic thin-film transistor is advantageous for monolithic three-dimensional integration attributed to low temperature and facile solution processing. However, the electrical properties of solution deposited organic semiconductor channels are very sensitive to the substrate surface and processing conditions. An organic-last integration technology is developed for wafer-scale heterogeneous integration of a multi-layer organic material stack from solution onto the non-even substrate surface of a III-V micro light emitting diode plane. A via process is proposed to make the via interconnection after fabrication of the organic thin-film transistor. Low-defect uniform organic semiconductor and dielectric layers can then be formed on top to achieve high-quality interfaces. The resulting organic thin-film transistors exhibit superior performance for driving micro light emitting diode displays, in terms of milliampere driving current, and large ON/OFF current ratio approaching 1010 with excellent uniformity and reliability. Active-matrix micro light emitting diode displays are demonstrated with highest brightness of 150,000 nits and highest resolution of 254 pixels-per-inch.