Approaching the intrinsic exciton physics limit in two-dimensional semiconductor diodes.

Two-dimensional (2D) semiconductors have attracted intense interest for their unique photophysical properties, including large exciton binding energies and strong gate tunability, which arise from their reduced dimensionality1-5. Despite considerable efforts, a disconnect persists between the fundamental photophysics in pristine 2D semiconductors and the practical device performances, which are often plagued by many extrinsic factors, including chemical disorder at the semiconductor-contact interface. Here, by using van der Waals contacts with minimal interfacial disorder, we suppress contact-induced Shockley-Read-Hall recombination and realize nearly intrinsic photophysics-dictated device performance in 2D semiconductor diodes. Using an electrostatic field in a split-gate geometry to independently modulate electron and hole doping in tungsten diselenide diodes, we discover an unusual peak in the short-circuit photocurrent at low charge densities. Time-resolved photoluminescence reveals a substantial decrease of the exciton lifetime from around 800 picoseconds in the charge-neutral regime to around 50 picoseconds at high doping densities owing to increased exciton-charge Auger recombination. Taken together, we show that an exciton-diffusion-limited model well explains the charge-density-dependent short-circuit photocurrent, a result further confirmed by scanning photocurrent microscopy. We thus demonstrate the fundamental role of exciton diffusion and two-body exciton-charge Auger recombination in 2D devices and highlight that the intrinsic photophysics of 2D semiconductors can be used to create more efficient optoelectronic devices.

High-order superlattices by rolling up van der Waals heterostructures.

Two-dimensional (2D) materials1,2 and the associated van der Waals (vdW) heterostructures3-7 have provided great flexibility for integrating distinct atomic layers beyond the traditional limits of lattice-matching requirements, through layer-by-layer mechanical restacking or sequential synthesis. However, the 2D vdW heterostructures explored so far have been usually limited to relatively simple heterostructures with a small number of blocks8-18. The preparation of high-order vdW superlattices with larger number of alternating units is exponentially more difficult, owing to the limited yield and material damage associated with each sequential restacking or synthesis step8-29. Here we report a straightforward approach to realizing high-order vdW superlattices by rolling up vdW heterostructures. We show that a capillary-force-driven rolling-up process can be used to delaminate synthetic SnS2/WSe2 vdW heterostructures from the growth substrate and produce SnS2/WSe2 roll-ups with alternating monolayers of WSe2 and SnS2, thus forming high-order SnS2/WSe2 vdW superlattices. The formation of these superlattices modulates the electronic band structure and the dimensionality, resulting in a transition of the transport characteristics from semiconducting to metallic, from 2D to one-dimensional (1D), with an angle-dependent linear magnetoresistance. This strategy can be extended to create diverse 2D/2D vdW superlattices, more complex 2D/2D/2D vdW superlattices, and beyond-2D materials, including three-dimensional (3D) thin-film materials and 1D nanowires, to generate mixed-dimensional vdW superlattices, such as 3D/2D, 3D/2D/2D, 1D/2D and 1D/3D/2D vdW superlattices. This study demonstrates a general approach to producing high-order vdW superlattices with widely variable material compositions, dimensions, chirality and topology, and defines a rich material platform for both fundamental studies and technological applications.

WASF3 disrupts mitochondrial respiration and may mediate exercise intolerance in myalgic encephalomyelitis/chronic fatigue syndrome.

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is characterized by various disabling symptoms including exercise intolerance and is diagnosed in the absence of a specific cause, making its clinical management challenging. A better understanding of the molecular mechanism underlying this apparent bioenergetic deficiency state may reveal insights for developing targeted treatment strategies. We report that overexpression of Wiskott-Aldrich Syndrome Protein Family Member 3 (WASF3), here identified in a 38-y-old woman suffering from long-standing fatigue and exercise intolerance, can disrupt mitochondrial respiratory supercomplex formation and is associated with endoplasmic reticulum (ER) stress. Increased expression of WASF3 in transgenic mice markedly decreased their treadmill running capacity with concomitantly impaired respiratory supercomplex assembly and reduced complex IV levels in skeletal muscle mitochondria. WASF3 induction by ER stress using endotoxin, well known to be associated with fatigue in humans, also decreased skeletal muscle complex IV levels in mice, while decreasing WASF3 levels by pharmacologic inhibition of ER stress improved mitochondrial function in the cells of the patient with chronic fatigue. Expanding on our findings, skeletal muscle biopsy samples obtained from a cohort of patients with ME/CFS showed increased WASF3 protein levels and aberrant ER stress activation. In addition to revealing a potential mechanism for the bioenergetic deficiency in ME/CFS, our study may also provide insights into other disorders associated with fatigue such as rheumatic diseases and long COVID.

Mitochondrial respiration reduces exposure of the nucleus to oxygen.

The endosymbiotic theory posits that ancient eukaryotic cells engulfed O2-consuming prokaryotes, which protected them against O2 toxicity. Previous studies have shown that cells lacking cytochrome c oxidase (COX), required for respiration, have increased DNA damage and reduced proliferation, which could be improved by reducing O2 exposure. With recently developed fluorescence lifetime microscopy-based probes demonstrating that the mitochondrion has lower [O2] than the cytosol, we hypothesized that the perinuclear distribution of mitochondria in cells may create a barrier for O2 to access the nuclear core, potentially affecting cellular physiology and maintaining genomic integrity. To test this hypothesis, we utilized myoglobin-mCherry fluorescence lifetime microscopy O2 sensors without subcellular targeting ("cytosol") or with targeting to the mitochondrion or nucleus for measuring their localized O2 homeostasis. Our results showed that, similar to the mitochondria, the nuclear [O2] was reduced by ∼20 to 40% compared with the cytosol under imposed O2 levels of ∼0.5 to 18.6%. Pharmacologically inhibiting respiration increased nuclear O2 levels, and reconstituting O2 consumption by COX reversed this increase. Similarly, genetic disruption of respiration by deleting SCO2, a gene essential for COX assembly, or restoring COX activity in SCO2-/- cells by transducing with SCO2 cDNA replicated these changes in nuclear O2 levels. The results were further supported by the expression of genes known to be affected by cellular O2 availability. Our study reveals the potential for dynamic regulation of nuclear O2 levels by mitochondrial respiratory activity, which in turn could affect oxidative stress and cellular processes such as neurodegeneration and aging.

Programmable Singlet Oxygen Battery for Automated Photodynamic Therapy Enabled by Pyridone-Pyridine Tautomer Engineering.

The efficacy of photodynamic therapy is hindered by the hypoxic environment in tumors and limited light penetration depth. The singlet oxygen battery (SOB) has emerged as a promising solution, enabling oxygen- and light-independent 1O2 release. However, conventional SOB systems typically exhibit an "always-ON" 1O2 release, leading to potential 1O2 leakage before and after treatment. This not only compromises therapeutic outcomes but also raises substantial biosafety concerns. In this work, we introduce a programmable singlet oxygen battery, engineered to address all the issues discussed above. The concept is illustrated through the development of a tumor-microenvironment-responsive pyridone-pyridine switch, PyAce, which exists in two tautomeric forms: PyAce-0 (pyridine) and PyAce (pyridone) with different 1O2 storage half-lives. In its native state, PyAce remains in the pyridone form, capable of storing 1O2 (t1/2 = 18.5 h). Upon reaching the tumor microenvironment, PyAce is switched to the pyridine form, facilitating rapid and thorough 1O2 release (t1/2 = 16 min), followed by quenched 1O2 release post-therapy. This mechanism ensures suppressed 1O2 production pre- and post-therapy with selective and rapid 1O2 release at the tumor site, maximizing therapeutic efficacy while minimizing side effects. The achieved "OFF-ON-OFF" 1O2 therapy showed high spatiotemporal selectivity and was independent of the oxygen supply and light illumination.

ATM-CHK2-Beclin 1 axis promotes autophagy to maintain ROS homeostasis under oxidative stress.

The homeostatic link between oxidative stress and autophagy plays an important role in cellular responses to a wide variety of physiological and pathological conditions. However, the regulatory pathway and outcomes remain incompletely understood. Here, we show that reactive oxygen species (ROS) function as signaling molecules that regulate autophagy through ataxia-telangiectasia mutated (ATM) and cell cycle checkpoint kinase 2 (CHK2), a DNA damage response (DDR) pathway activated during metabolic and hypoxic stress. We report that CHK2 binds to and phosphorylates Beclin 1 at Ser90/Ser93, thereby impairing Beclin 1-Bcl-2 autophagy-regulatory complex formation in a ROS-dependent fashion. We further demonstrate that CHK2-mediated autophagy has an unexpected role in reducing ROS levels via the removal of damaged mitochondria, which is required for cell survival under stress conditions. Finally, CHK2-/- mice display aggravated infarct phenotypes and reduced Beclin 1 p-Ser90/Ser93 in a cerebral stroke model, suggesting an in vivo role of CHK2-induced autophagy in cell survival. Taken together, these results indicate that the ROS-ATM-CHK2-Beclin 1-autophagy axis serves as a physiological adaptation pathway that protects cells exposed to pathological conditions from stress-induced tissue damage.

Comprehensive Genomic and Transcriptomic Analysis of Sclerosing Pneumocytoma.

Sclerosing pneumocytoma is a rare and distinct lung neoplasm whose histogenesis and molecular alterations are the subject of ongoing research. Our recent study revealed that AKT1 internal tandem duplications (ITD), point mutations, and short indels were present in almost all tested sclerosing pneumocytomas, suggesting that AKT1 mutations are a major driving oncogenic event in this tumor. Although the pathogenic role of AKT1 point mutations is well established, the significance of AKT1 ITD in oncogenesis remains largely unexplored. We conducted comprehensive genomic and transcriptomic analyses of sclerosing pneumocytoma to address this knowledge gap. RNA-sequencing data from 23 tumors and whole-exome sequencing data from 44 tumors were used to obtain insights into their genetic and transcriptomic profiles. Our analysis revealed a high degree of genetic and transcriptomic similarity between tumors carrying AKT1 ITD and those with AKT1 point mutations. Mutational signature analysis revealed COSMIC signatures 1 and 5 as the prevailing signatures of sclerosing pneumocytoma, associated with the spontaneous deamination of 5-methylcytosine and an unknown etiology, respectively. RNA-sequencing data analysis revealed that the sclerosing pneumocytoma gene expression profile is characterized by activation of the PI3K/AKT/mTOR pathway, which exhibits significant similarity between tumors harboring AKT1 ITD and those with AKT1 point mutations. Notably, an upregulation of SOX9, a transcription factor known for its involvement in fetal lung development, was observed in sclerosing pneumocytoma. Specifically, SOX9 expression was prominent in the round cell component, whereas it was relatively lower in the surface cell component of the tumor. To the best of our knowledge, this is the first comprehensive investigation of the genomic and transcriptomic characteristics of sclerosing pneumocytoma. Results of the present study provide insights into the molecular attributes of sclerosing pneumocytoma and a basis for future studies of this enigmatic tumor.

Development of CRISPR/Cas Delivery Systems for In Vivo Precision Genome Editing.

ConspectusClustered, regularly interspaced, short palindromic repeat (CRISPR)/associated protein 9 (CRISPR/Cas9) is emerging as a powerful genome-editing tool, enabling precise and targeted modifications of virtually any genomic sequence in living cells. These technologies have potential therapeutic applications for cancers, metabolic diseases, and genetic disorders. However, several major challenges hinder the full realization of their potential. Specifically, CRISPR-Cas9 gene editors, whether delivered as plasmid DNA, mRNA/sgRNA, or ribonucleoprotein (RNP), exhibit poor membrane permeability, restricting their access to the intracellular genome, where the editing occurs. Additionally, these editors lack tissue or organ specificity, raising concerns about off-target editing at the tissue level that causes unwanted genotoxicity. Though a range of delivery carriers has been developed to deliver Cas9 editors, their effectiveness is often limited by a number of barriers at both the extracellular and intracellular levels. Moreover, the prolonged activity of Cas9 increases the risk of off-target editing at the genomic level. Therefore, it is crucial to develop efficient delivery vectors, along with molecular switches to safely regulate Cas9 activity.In this Account, we summarize our recent achievements in developing different types of materials that can efficiently deliver the plasmid DNA encoding Cas9 protein and single-guide RNA (sgRNA), or Cas9 RNP into cells to highlight the design considerations of carriers for safe and efficient delivery in vitro and in vivo. After elucidating the chemical and physical factors that are responsible for encapsulating and delivering these biomacromolecules, we further elucidate how we design the biodegradable polymeric carriers using dynamic disulfide chemistry, emphasize their safe and efficient delivery features for genome-editing biomacromolecules, and also introduce the integration of the intracellular delivery of genome-editing biomacromolecules with microneedle-based transdermal delivery to promote therapeutic genome editing for inflammatory skin disorders. Finally, we review how we exploit optical, chemical, and genetic switches to control the Cas9 activity in conjunction with targeted delivery to address the spatiotemporal specificity of gene editing in vivo and demonstrate their precision therapy against cancer and colitis treatment as proof-of-concept examples. In the final part, we will summarize the progress we have made and propose the future directions that may impact the field based on our own research outcomes.

CRISPR-Based KCC2 Upregulation Attenuates Drug-Resistant Seizure in Mouse Models of Epilepsy.

OBJECTIVE: The precise intervention of K-Cl cotransporter isoform 2 (KCC2) as a promising target for drug-resistant epilepsy remains elusive. METHODS: Here, we used a CRISPRa system delivered by adeno-associated viruses to specifically upregulate KCC2 in the subiculum to confirm its therapeutic potential in various in vivo epilepsy models. Calcium fiber photometry was used to reveal the role of KCC2 in the restoration of impaired GABAergic inhibition. RESULTS: CRISPRa system effectively upregulated KCC2 expression both in in vitro cell culture and in vivo brain region. Delivery of CRISPRa with adeno-associated viruses resulted in upregulating the subicular KCC2 level, contributing to alleviating the severity of hippocampal seizure and facilitating the anti-seizure effect of diazepam in a hippocampal kindling model. In a kainic acid-induced epilepticus status model, KCC2 upregulation greatly increased the termination percentage of diazepam-resistant epilepticus status with the broadened therapeutic window. More importantly, KCC2 upregulation attenuated valproate-resistant spontaneous seizure in a kainic acid-induced chronic epilepsy model. Finally, calcium fiber photometry showed CRISPRa-mediated KCC2 upregulation partially restored the impaired GABAA -mediated inhibition in epilepsy. INTERPRETATION: These results showed the translational potential of adeno-associated viruses-mediated delivery of CRISPRa for treating neurological disorders by modulating abnormal gene expression that is directly associated with neuronal excitability, validating KCC2 as a promising therapeutic target for treating drug-resistant epilepsy. ANN NEUROL 2023;94:91-105.

Improvement of lipopeptide production in Bacillus subtilis HNDF2-3 by overexpression of the sfp and comA genes.

Bacillus subtilis HNDF2-3 can produce a variety of lipopeptide antibiotics with lower production. To improve its lipopeptide production, three genetically engineered strains were constructed. The results of real-time PCR showed that the highest transcriptional levels of the sfp gene in F2-3sfp, F2-3comA and F2-3sfp-comA were 29.01, 6.65 and 17.50 times of the original strain, respectively, while the highest transcriptional levels of the comA gene in F2-3comA and F2-3sfp-comA were 10.44 and 4.13 times of the original strain, respectively. The results of ELISA showed that the malonyl-CoA transacylase activity of F2-3comA was the highest, reaching 18.53 IU/L at 24 h, the data was 32.74% higher than that of the original strain. The highest total lipopeptide production of F2-3sfp, F2-3comA and F2-3sfp-comA induced by IPTG at optimal concentration were 33.51, 46.05 and 38.96% higher than that of the original strain, respectively. The results of HPLC showed that iturin A production of F2-3sfp-comA was the highest, which was 63.16% higher than that of the original strain. This study laid the foundation for further construction of genetically engineered strains with high lipopeptide production.

Supramolecular Genome Editing: Targeted Delivery and Endogenous Activation of CRISPR/Cas9 by Dynamic Host-Guest Recognition.

We synthesize supramolecular poly(disulfide) (CPS) containing covalently attached cucurbit[7]uril (CB[7]), which is exploited not only as a carrier to deliver plasmid DNA encoding destabilized Cas9 (dsCas9), but also as a host to include trimethoprim (TMP) by CB[7] moieties through the supramolecular complexation to form TMP@CPS/dsCas9. Once the plasmid is transfected into tumor cells by CPS, the presence of polyamines can competitively trigger the decomplexation of TMP@CPS, thereby displacing and releasing TMP from CB[7] to stabilize dsCas9 that can target and edit the genomic locus of PLK1 to inhibit the growth of tumor cells. Following the systemic administration of TMP@CPS/dsCas9 decorated with hyaluronic acid (HA), tumor-specific editing of PLK1 is detected due to the elevated polyamines in tumor microenvironment, greatly minimizing off-target editing in healthy tissues and non-targeted organs. As the metabolism of polyamines is dysregulated in a wide range of disorders, this study offers a supramolecular approach to precisely control CRISPR/Cas9 functions under particular pathological contexts.

A Self-Assembly Nano-Prodrug for Combination Therapy in Triple-Negative Breast Cancer Stem Cells.

Triple-negative breast cancer (TNBC) displays a highly aggressive nature that originates from a small subpopulation of TNBC stem cells (TNBCSCs), and these TNBCSCs give rise to chemoresistance, tumor metastasis, and recurrence. Unfortunately, traditional chemotherapy eradicates normal TNBC cells but fails to kill quiescent TNBCSCs. To explore a new strategy for eradicating TNBCSCs, a disulfide-mediated self-assembly nano-prodrug that can achieve the co-delivery of ferroptosis drug, differentiation-inducing agent, and chemotherapeutics for simultaneous TNBCSCs and TNBC treatment, is reported. In this nano-prodrug, the disulfide bond not only induces self-assembly behavior of different small molecular drug but also serves as a glutathione (GSH)-responsive trigger in controlled drug release. More importantly, the differentiation-inducing agent can transform TNBCSCs into normal TNBC cells, and this differentiation with chemotherapeutics provides an effective approach to indirectly eradicate TNBCSCs. In addition, ferroptosis therapy is essentially different from the apoptosis-induced cell death of differentiation or chemotherapeutic, which causes cell death to both TNBCSCs and normal TNBC cells. In different TNBC mouse models, this nano-prodrug significantly improves anti-tumor efficacy and effectively inhibits the tumor metastasis. This all-in-one strategy enables controlled drug release and reduces stemness-related drug resistance, enhancing the chemotherapeutic sensitivity in TNBC treatment.

Constant p.L424H Mutation in GTF2I in Micronodular Thymomas With Lymphoid Stroma: Evidence Supporting Close Relationship With Type A and AB Thymomas.

Micronodular thymoma with lymphoid stroma is a rare thymic neoplasm characterized by discrete nodules of epithelial tumor cells separated by abundant lymphoid stroma. The genetic features of micronodular thymoma with lymphoid stroma remain largely unexplored. Owing to the interference of abundant intratumoral, nonneoplastic lymphoid cells, a highly sensitive approach is necessary to study genetic changes in these tumors. In this study, we used a highly sensitive next-generation sequencing assay using the molecular barcoding Ion AmpliSeq HD technology to study the most commonly mutated genes in thymomas, including GTF2I, HRAS, NRAS, KRAS, and TP53. A total of 12 cases of micronodular thymomas with lymphoid stroma were tested, and 2 cases also had areas of type A thymoma in their tumor bed. Two micronodular thymic carcinomas with lymphoid stroma, a histological mimic of micronodular thymoma, were also included for comparison. Recurrent p.L424H mutations in GTF2I were found in all the cases of micronodular thymoma with lymphoid stroma but not in the cases of micronodular thymic carcinomas. In addition, 3 cases of micronodular thymoma with lymphoid stroma also had concomitant HRAS and/or KRAS mutations. Our study showed that p.L424H mutations in GTF2I is a constant genetic feature of micronodular thymoma with lymphoid stroma. This finding strongly suggests that micronodular thymoma with lymphoid stroma is closely related to type A and AB thymomas because they all share p.L424H mutations in GTF2I.

Genomic Profiling With Large-Scale Next-Generation Sequencing Panels Distinguishes Separate Primary Lung Adenocarcinomas From Intrapulmonary Metastases.

The distinction between different separate primary lung cancers (SPLCs) and intrapulmonary metastases (IPMs) is a challenging but clinically significant issue. Histopathology-based classification is the current practice; however, it is subjective and affected by interobserver variability. Recently, next-generation sequencing (NGS) panels have been used in lung cancer diagnostics. This study aimed to investigate the value of large-scale NGS panels for distinguishing between SPLCs and IPMs. A total of 32 patients with 69 lung adenocarcinomas were included. Comprehensive histopathologic assessments of multiple pulmonary adenocarcinomas were performed independently by 3 pathologists. The consensus of histopathologic classification was determined by a majority vote. Genomic analysis was performed using an amplicon-based large-scale NGS panel, targeting single-nucleotide variants and short insertions and deletions in 409 genes. Tumor pairs were classified as SPLCs or IPMs according to a predefined molecular classification algorithm. Using NGS and our molecular classification algorithm, 97.6% of the tumor pairs can be unambiguously classified as SPLCs or IPMs. The molecular classification was predictive of postoperative clinical outcomes in terms of overall survival (P = .015) and recurrence-free interval (P = .0012). There was a moderate interobserver agreement regarding histopathologic classification (κ = 0.524 at the tumor pair level). The concordance between histopathologic and molecular classification was 100% in cases where pathologists reached a complete agreement but only 53.3% where they did not. This study showed that large-scale NGS panels are a powerful modality that can help distinguish SPLCs from IPMs in patients with multiple lung adenocarcinomas and objectively provide accurate risk stratification.

Nuclear spin polarization and control in hexagonal boron nitride.

Electron spins in van der Waals materials are playing a crucial role in recent advances in condensed-matter physics and spintronics. However, nuclear spins in van der Waals materials remain an unexplored quantum resource. Here we report optical polarization and coherent control of nuclear spins in a van der Waals material at room temperature. We use negatively charged boron vacancy ([Formula: see text]) spin defects in hexagonal boron nitride to polarize nearby nitrogen nuclear spins. We observe the Rabi frequency of nuclear spins at the excited-state level anti-crossing of [Formula: see text] defects to be 350 times larger than that of an isolated nucleus, and demonstrate fast coherent control of nuclear spins. Further, we detect strong electron-mediated nuclear-nuclear spin coupling that is five orders of magnitude larger than the direct nuclear-spin dipolar coupling, enabling multi-qubit operations. Our work opens new avenues for the manipulation of nuclear spins in van der Waals materials for quantum information science and technology.

Extracellular Acidity Reprograms Macrophage Metabolism and Innate Responsiveness.

Although organ hypofunction and immunosuppression are life-threatening features of severe sepsis, the hypofunctioning organs and immune cells usually regain normal functionality if patients survive. Because tissue interstitial fluid can become acidic during the septic response, we tested the hypothesis that low extracellular pH (pHe) can induce reversible metabolic and functional changes in peritoneal macrophages from C57BL/6J mice. When compared with macrophages cultured at normal pHe, macrophages living in an acidic medium used less glucose and exogenous fatty acid to produce ATP. Lactate, glutamine, and de novo-synthesized fatty acids supported ATP production by mitochondria that gained greater mass, maximal oxygen consumption rate, and spare respiratory capacity. The cells transitioned to an M2-like state, with altered immune responses to LPS and slightly decreased phagocytic ability, yet they regained basal energy production, normal mitochondrial function, and proinflammatory responsiveness when neutral pHe was restored. Low pHe induces changes that support macrophage survival while rendering the cells less proinflammatory (more "tolerant") and less able to phagocytose bacteria. Macrophage responses to low interstitial pH may contribute to the reversible organ hypofunction and immunoparalysis noted in many patients with sepsis.

Near-infrared optogenetic engineering of photothermal nanoCRISPR for programmable genome editing.

We herein report an optogenetically activatable CRISPR-Cas9 nanosystem for programmable genome editing in the second near-infrared (NIR-II) optical window. The nanosystem, termed nanoCRISPR, is composed of a cationic polymer-coated Au nanorod (APC) and Cas9 plasmid driven by a heat-inducible promoter. The APC not only serves as a carrier for intracellular plasmid delivery but also can harvest external NIR-II photonic energy and convert it into local heat to induce the gene expression of the Cas9 endonuclease. Due to high transfection activity, the APC shows strong ability to induce a significant level of disruption in different genomic loci upon optogenetic activation. Moreover, the precise control of genome-editing activity can be simply programmed by finely tuning exposure time and irradiation time in vitro and in vivo and also enables editing at multiple time points, thus proving the sensitivity and inducibility of such an editing modality. The NIR-II optical feature of nanoCRISPR enables therapeutic genome editing at deep tissue, by which treatment of deep tumor and rescue of fulminant hepatic failure are demonstrated as proof-of-concept therapeutic examples. Importantly, this modality of optogenetic genome editing can significantly minimize the off-target effect of CRISPR-Cas9 in most potential off-target sites. The optogenetically activatable CRISPR-Cas9 nanosystem we have developed offers a useful tool to expand the current applications of CRISPR-Cas9, and also defines a programmable genome-editing strategy toward high precision and spatial specificity.

Cocultivation with Solanum nigrum and inoculation with Rhizophagus intraradices can improve plant photosynthesis and antioxidant defense to alleviate cadmium toxicity to soybean.

High Cd pollution can damage plant physiology and seriously threaten ecological security and human health. Therefore, we designed a cropping system, arbuscular mycorrhizal fungi (AMF) - soybean - Solanum nigrum L., to solve the high Cd pollution problem in an environmentally and economically friendly way. The results showed that AMF were able to break free from the constraints of cocultivation and still promote plant photosynthesis and growth in combined treatments to resist Cd stress. In addition, cocultivation combined with AMF improved the antioxidant defense to scavenge reactive oxygen species by promoting the production of antioxidant enzymes and nonenzyme substances in host plants. The glutathione content in soybean and the catalase activity in nightshade were recorded at the highest values under cocultivation combined with AMF treatment, which were 23.68% and 129.12% higher than those of monoculture without AMF treatments. The improvement in antioxidant defense alleviated oxidative stress, which was manifested by the reduction in Cd dense electronic particles in the ultrastructure and a 26.38% decrease in MDA content. Furthermore, this cropping mode combined the advantages of cocultivation to improve the Cd extraction efficiency and Rhizophagus intraradices to limit Cd accumulation and transport so that Cd was more accumulated and restricted in the roots of the cocultivated Solanum nigrum L., and the Cd concentration in soybean beans was reduced by 56% compared with the soybean monoculture without AMF treatment. Therefore, we suggest that this cropping system is a comprehensive and mild remediation technology suitable for highly Cd-contaminated soil.

Berberine ameliorates depression-like behavior in CUMS mice by activating TPH1 and inhibiting IDO1-associated with tryptophan metabolism.

Berberine, which is a potential antidepressant, exhibits definite efficiency in modulating the gut microbiota. Depressive behaviors in mice induced using chronic unpredictable mild stress (CUMS) stimulation were evaluated by behavioral experiments. The markers of neurons and synapses were measured using immunohistochemical staining. An enzyme-linked immunosorbent assay was adopted to analyze serum inflammatory cytokines levels and neurotransmitters were evaluated by LC-MS/MS. Untargeted metabolomics of tryptophan metabolism was further performed using LC-MS/MS. The target enzymes of berberine involved in tryptophan metabolism were assayed using AutoDock and GRMACS softwares. Then, antibiotics was utilized to induce intestinal flora disturbance. Berberine improved the depressive behaviors of mice in a microbiota-dependent manner. Increased neurons and synaptic plasticity were observed following berberine treatment. Meanwhile, berberine decreased serum levels of TNF-α, IL-1ß, and IL-4 and increased levels of IL-10. Moreover, berberine induced retraction of the abnormal neurotransmitters and metabolomics assays revealed that berberine promoted tryptophan biotransformation into serotonin and inhibited the kynurenine metabolism pathway, which was attributed to the potential agonist of tryptophan 5-hydroxylase 1 (TPH1) and inhibitor of indoleamine 2,3-dioxygenase 1 (IDO1). In conclusion, berberine improves depressive symptoms in CUMS-stimulated mice by targeting both TPH1 and IDO1, which are involved in tryptophan metabolism.

Activatable Type I Photosensitizer with Quenched Photosensitization Pre and Post Photodynamic Therapy.

The phototoxicity of photosensitizers (PSs) pre and post photodynamic therapy (PDT), and the hypoxic tumor microenvironment are two major problems limiting the application of PDT. While activatable PSs can successfully address the PS phototoxicity pre PDT, and type I PS can generate reactive oxygen species (ROS) effectively in hypoxic environment, very limited approaches are available for addressing the phototoxicity post PDT. There is virtually no solution available to address all these issues using a single design. Herein, we propose a proof-of-concept on-demand switchable photosensitizer with quenched photosensitization pre and post PDT, which could be activated only in tumor hypoxic environment. Particularly, a hypoxia-normoxia cycling responsive type I PS TPFN-AzoCF3 was designed to demonstrate the concept, which was further formulated into TPFN-AzoCF3 nanoparticles (NPs) using DSPE-PEG-2000 as the encapsulation matrix. The NPs could be activated only in hypoxic tumors to generate type I ROS during PDT treatment, but remain non-toxic in normal tissues, pre or after PDT, thus minimizing side effects and improving the therapeutic effect. With promising results in in vitro and in vivo tumor treatment, this presented strategy will pave the way for the design of more on-demand switchable photosensitizers with minimized side effects in the future.