Circuit Architecture of VTA Dopamine Neurons Revealed by Systematic Input-Output Mapping.

Dopamine (DA) neurons in the midbrain ventral tegmental area (VTA) integrate complex inputs to encode multiple signals that influence motivated behaviors via diverse projections. Here, we combine axon-initiated viral transduction with rabies-mediated trans-synaptic tracing and Cre-based cell-type-specific targeting to systematically map input-output relationships of VTA-DA neurons. We found that VTA-DA (and VTA-GABA) neurons receive excitatory, inhibitory, and modulatory input from diverse sources. VTA-DA neurons projecting to different forebrain regions exhibit specific biases in their input selection. VTA-DA neurons projecting to lateral and medial nucleus accumbens innervate largely non-overlapping striatal targets, with the latter also sending extensive extra-striatal axon collaterals. Using electrophysiology and behavior, we validated new circuits identified in our tracing studies, including a previously unappreciated top-down reinforcing circuit from anterior cortex to lateral nucleus accumbens via VTA-DA neurons. This study highlights the utility of our viral-genetic tracing strategies to elucidate the complex neural substrates that underlie motivated behaviors.

Protease-Driven Phase Separation of Elastin-Like Polypeptides.

Elastin-like polypeptides (ELPs) are a promising material platform for engineering stimuli-responsive biomaterials, as ELPs undergo phase separation above a tunable transition temperature. ELPs with phase behavior that is isothermally regulated by biological stimuli remain attractive for applications in biological systems. Herein, we report protease-driven phase separation of ELPs. Protease-responsive "cleavable" ELPs comprise a hydrophobic ELP block connected to a hydrophilic ELP block by a protease cleavage site linker. The hydrophilic ELP block acts as a solubility tag for the hydrophobic ELP block, creating a temperature window in which the cleavable ELP reactant is soluble and the proteolytically generated hydrophobic ELP block is insoluble. Within this temperature window, isothermal, protease-driven phase separation occurs when a critical concentration of hydrophobic cleavage product accumulates. Furthermore, protease-driven phase separation is generalizable to four compatible protease-cleavable ELP pairings. This work presents exciting opportunities to regulate ELP phase behavior in biological systems using proteases.

Triethyl amine as an effective reducing agent for sulfoxide deoxygenation.

Enabled by triethyl amine (Et3N) and thionyl chloride (SOCl2), an efficient and practical protocol for deoxygenation of sulfoxide to sulfide was developed. This new method features a wide range of substrate scope, including diaryl, dialkyl and aryl alkyl substituted sulfoxides. Detailed mechanistic investigations reveal the crucial role played by Et3N as an electron-donating reductant rather than a hydrogen-atom donor.

100Gb/s coherent optical secure communication over 1000†km based on analog-digital hybrid chaos.

In recent years, the transmission capacity of chaotic secure communications has been greatly expanded by combining coherent detection and multi-dimensional multiplexing. However, demonstrations over 1000 km fiber are yet to be further explored. In this paper, we propose a coherent optical secure transmission system based on analog-digital hybrid chaos. By introducing an analog-digital converter (ADC) and a bit extraction into the feedback loop of entropy source, the broadband analog chaos is converted into a binary digital signal. This binary digital signal is then mapped to a 65536-level pulse amplitude modulation (PAM) signal and injected into the semiconductor laser (SL) to regenerate the analog chaos, forming a closed loop. The binary digital signal from the chaos source and the encrypted signal are transmitted via wavelength division multiplexing (WDM). By using conventional digital signal processing (DSP) algorithms and neural networks for post-compensation, long-haul high-quality chaotic synchronization and high-performance secure communication are achieved. In addition, the probability density distribution of the analog chaotic signal is effectively improved by adopting the additional higher-order mapping operation in the digital part of the chaos source. The proof-of-concept experimental results show that our proposed scheme can support the secure transmission of 100 Gb/s quadrature phase shift keying (QPSK) signals over 1000 km of standard single-mode fiber (SSMF). The decrypted bit error rate (BER) reaches 9.88 × 10-4, which is well below the 7% forward error correction (FEC) threshold (BER = 3.8 × 10-3). This research provides a potential solution for high-capacity long-haul chaotic optical communications and fills the gap in secure communications based on analog-digital hybrid chaos.

Secure key distribution based on the polarization reciprocity of fiber and a coherent reception architecture.

Secure key distribution (SKD) schemes based on the interaction between a broadband chaotic source and the reciprocity of a fiber channel exhibit reliable security and a high key generation rate (KGR). However, under the intensity modulation and direct detection (IM/DD) architecture, these SKD schemes cannot achieve a long distribution distance due to the limitations on the signal-to-noise ratio (SNR) and the receiver's sensitivity. Here, based on the advantage of the high sensitivity of coherent reception, we design a coherent-SKD structure where orthogonal polarization states are locally modulated by a broadband chaotic signal and the single-frequency local oscillator (LO) light is transmitted bidirectionally in the optical fiber. The proposed structure not only utilizes the polarization reciprocity of optical fiber but also largely eliminates the non-reciprocity factor, which can effectively extend the distribution distance. The experiment realized an error-free SKD with a transmission distance of 50 km and a KGR of 1.85 Gbit/s.

Insights into Adaptive Regulation of the Leaf-Petiole System: Strategies for Survival of Water Lily Plants under Salt Stress.

The water lily (Nymphaea tetragona) is an ancient angiosperm that belongs to the Nymphaeaceae family. As a rooted floating-leaf plant, water lilies are generally cultivated in fresh water, therefore, little is known about their survival strategies under salt stress. Long-term salt stress causes morphological changes, such as the rapid regeneration of floating leaves and a significant decrease in leaf number and surface area. We demonstrate that salt stress induces toxicity soon after treatment, but plants can adapt by regenerating floating leaves that are photosynthetically active. Transcriptome profiling revealed that ion binding was one of the most-enriched GO terms in leaf-petiole systems under salt stress. Sodium-transporter-related genes were downregulated, whereas K+ transporter genes were both up- and downregulated. These results suggest that restricting intracellular Na+ importing while maintaining balanced K+ homeostasis is an adaptive strategy for tolerating long-term salt stress. ICP-MS analysis identified the petioles and leaves as Na-hyperaccumulators, with a maximum content of over 80 g kg-1 DW under salt stress. Mapping of the Na-hyperaccumulation trait onto the phylogenetic relationships revealed that water lily plants might have a long evolutionary history from ancient marine plants, or may have undergone historical ecological events from salt to fresh water. Ammonium transporter genes involved in nitrogen metabolism were downregulated, whereas NO3--related transporters were upregulated in both the leaves and petioles, suggesting a selective bias toward NO3- uptake under salt stress. The morphological changes we observed may be due to the reduced expression of genes related to auxin signal transduction. In conclusion, the floating leaves and submerged petioles of the water lily use a series of adaptive strategies to survive salt stress. These include the absorption and transport of ions and nutrients from the surrounding environments, and the ability to hyperaccumulate Na+. These adaptations may serve as the physiological basis for salt tolerance in water lily plants.

Time delay estimation from the time series for optical chaos systems using deep learning.

We propose a model-free time delay signature (TDS) extraction method for optical chaos systems. The TDS can be identified from time series without prior knowledge of the actual physical processes. In optical chaos secure communication systems, the chaos carrier is usually generated by a laser diode subject to opto-electronic/all-optical time delayed feedback. One of the most important factors to security considerations is the concealment of the TDS. So far, statistical analysis methods such as autocorrelation function (ACF) and delayed mutual information (DMI) are usually used to unveil the TDS. However, the effectiveness of these methods will be reduced when increasing the nonlinearity of chaos systems. Meanwhile, certain TDS concealment strategies have been designed against statistical analysis. In our previous work, convolutional neural network shows its effectiveness on TDS extraction of chaos systems with high loop nonlinearity. However, this method relies on the knowledge of detailed structure of the chaos systems. In this work, we formulate a blind identification method based on long short-term memory neural network (LSTM-NN) model. The method is validated against the two major types of optical chaos systems, i.e. opto-electronic oscillator (OEO) chaos system and laser chaos system based on internal nonlinearity. Moreover, some security enhanced chaotic systems are also studied. The results show that the proposed method has high tolerance to additive noise. Meanwhile, the data amount needed is less than existing methods.

Viral-genetic tracing of the input-output organization of a central noradrenaline circuit.

Deciphering how neural circuits are anatomically organized with regard to input and output is instrumental in understanding how the brain processes information. For example, locus coeruleus noradrenaline (also known as norepinephrine) (LC-NE) neurons receive input from and send output to broad regions of the brain and spinal cord, and regulate diverse functions including arousal, attention, mood and sensory gating. However, it is unclear how LC-NE neurons divide up their brain-wide projection patterns and whether different LC-NE neurons receive differential input. Here we developed a set of viral-genetic tools to quantitatively analyse the input-output relationship of neural circuits, and applied these tools to dissect the LC-NE circuit in mice. Rabies-virus-based input mapping indicated that LC-NE neurons receive convergent synaptic input from many regions previously identified as sending axons to the locus coeruleus, as well as from newly identified presynaptic partners, including cerebellar Purkinje cells. The 'tracing the relationship between input and output' method (or TRIO method) enables trans-synaptic input tracing from specific subsets of neurons based on their projection and cell type. We found that LC-NE neurons projecting to diverse output regions receive mostly similar input. Projection-based viral labelling revealed that LC-NE neurons projecting to one output region also project to all brain regions we examined. Thus, the LC-NE circuit overall integrates information from, and broadcasts to, many brain regions, consistent with its primary role in regulating brain states. At the same time, we uncovered several levels of specificity in certain LC-NE sub-circuits. These tools for mapping output architecture and input-output relationship are applicable to other neuronal circuits and organisms. More broadly, our viral-genetic approaches provide an efficient intersectional means to target neuronal populations based on cell type and projection pattern.

Study of stability and interference for catecholamines and metanephrines, 3-methoxytyramine: key point of an accurate diagnosis for pheochromocytoma and paraganglioma.

BACKGROUND: Accurate diagnosis of pheochromocytoma and paraganglioma (PPGLs) is highly dependent on the detection of metanephrines and catecholamines. However, the systematic investigation on influencing factors including specimen (plasma or whole blood), anticoagulant, storage conditions, and interference factors need further confirmation. METHODS: Blood with heparin-lithium or EDTA-K2 were collected, stability of epinephrine (EPI), norepinephrine (NE), dopamine (DA), metanephrine (MN), normetanephrine (NMN), 3-methoxytyramine (3-MT) in whole blood and plasma at room temperature and 4 °C for different storage times, stability of plasma MN, NMN and 3-MT at -20 °C and -80 °C were investigated. Plasma with hemoglobin (1 g/L, 2 g/L, 3 g/L, 4 g/L, 6 g/L), TG (<5 mmol/L, 5-8 mmol/L, >8 mmol/L) were prepared. RESULTS: EPI, NE, DA were prone to degrade at room temperature, samples should be centrifuged at 4 °C. EPI and NE were stable in whole blood at 4 °C for 4 h and in plasma for 2 h. For MN, NMN, 3-MT, plasma can be stable at room temperature and 4 °C for at least 6 h, which is better than whole blood; there was no significant difference when stored at -20 °C and -80 °C for 7 days. Heparin-lithium had a slight advantage over EDTA-K2. EPI, NE, DA should not be performed when Hb > 1 g/L or TG > 5 mmol/L. MN, NMN, 3-MT should not be performed when Hb > 2 g/L, whereas TG had no interference. CONCLUSIONS: According to the actual clinical application scenario, this study provided a reliable basis for the accurate diagnosis of PPGLs.

Multi-in-One: Multiple-Proteases, One-Hour-Shot Strategy for Fast and High-Coverage Phosphoproteomic Investigation.

Although a multiple-protease based shotgun proteomics method was shown to improve coverage for phosphosite identification, this traditional pipeline is time-consuming and can be of low reproducibility. Here, we demonstrated a multi-in-one strategy to saturate the phosphosite coverage by combining the multiple-proteases based digestion, one-step enrichment, and one-shot data-independent acquisition (DIA) as short as 1 h. In the "three-in-one" workflow, more than 19,700 and 13,500 phosphosites could be identified in the trypsin-like and nontrypsin-like mixture, respectively. By combining and applying our "three-in-one" strategy, nearly 30,000 phosphosites could be successfully quantified with high reproducibility across samples. Meanwhile, we developed a faster and more robust method, in which over a single 66 min chromatographic method by "six-in-one" strategy, 19,445 phosphosites could be successfully localized, drastically reducing the database search time required in the traditional method. Inspiringly, this strategy further enabled us to discover 2,675 phosphorylation events on the low abundant transcription factors (TFs) in living cells with high coverage. More broadly, the multi-in-one strategy makes the multiple-protease digestion in large-scale analysis applicable, with low time-consuming, high sensitivity, improved coverage, and high reproducibility.

Robust chaotic-shift-keying scheme based on electro-optical hybrid feedback system.

A chaotic-shift-keying (CSK) scheme is designed based on a chaos system with electro-optical hybrid time delayed feedback structure. By switching the time delay parameter as a message feeding method, the generated chaotic signal is no longer suffered from return map attack, which is an innate vulnerability of traditional CSK. When the coupling of the seed electrical chaotic system and the nonlinear optical time delay feedback loop is carefully weighed, this CSK scheme shows a good robustness in terms of handling noise for transmitting digital signals. By demodulating the digital signals with the chaotic coherent detection method, a bit error rate of 6×10-4 is achieved at the signal-to-noise ratio of 10dB in the simulation. The proposed method has a promising application prospect in some harsh environments.

Unveil the time delay signature of optical chaos systems with a convolutional neural network.

We propose a time delay signature extraction method for optical chaos systems based on a convolutional neural network. Through transforming the time delay signature of a one-dimensional time series into two-dimensional image features, the excellent ability of convolutional neural networks for image feature recognition is fully utilized. The effectiveness of the method is verified on chaos systems with opto-electronic feedback and all optical feedback. The recognition accuracy of the method is 100% under normal conditions. For the system with extremely strong nonlinearity, the accuracy can be 93.25%, and the amount of data required is less than traditional methods. Moreover, it is verified that the proposed method possesses a strong ability to withstand the effects of noise.

A versatile in vivo system for directed dissection of gene expression patterns.

Tissue-specific gene expression using the upstream activating sequence (UAS)­GAL4 binary system has facilitated genetic dissection of many biological processes in Drosophila melanogaster. Refining GAL4 expression patterns or independently manipulating multiple cell populations using additional binary systems are common experimental goals. To simplify these processes, we developed a convertible genetic platform, the integrase swappable in vivo targeting element (InSITE) system. This approach allows GAL4 to be replaced with any other sequence, placing different genetic effectors under the control of the same regulatory elements. Using InSITE, GAL4 can be replaced with LexA or QF, allowing an expression pattern to be repurposed. GAL4 can also be replaced with GAL80 or split-GAL4 hemi-drivers, allowing intersectional approaches to refine expression patterns. The exchanges occur through efficient in vivo manipulations, making it possible to generate many swaps in parallel. This system is modular, allowing future genetic tools to be easily incorporated into the existing framework.

Post-Transcriptional Modular Synthetic Receptors.

Inspired by the power of transcriptional synthetic receptors and hoping to complement them to expand the toolbox for cell engineering, we establish LIDAR (Ligand-Induced Dimerization Activating RNA editing), a modular post-transcriptional synthetic receptor platform that harnesses RNA editing by ADAR. LIDAR is compatible with various receptor architectures in different cellular contexts, and enables the sensing of diverse ligands and the production of functional outputs. Furthermore, LIDAR can sense orthogonal signals in the same cell and produce synthetic spatial patterns, potentially enabling the programming of complex multicellular behaviors. Finally, LIDAR is compatible with compact encoding and can be delivered by synthetic mRNA. Thus, LIDAR expands the family of synthetic receptors, holding the promise to empower basic research and therapeutic applications.

Roles of Kruppel-associated Box (KRAB)-associated Co-repressor KAP1 Ser-473 Phosphorylation in DNA Damage Response.

The Kruppel-associated box (KRAB)-associated co-repressor KAP1 is an essential nuclear co-repressor for the KRAB zinc finger protein superfamily of transcriptional factors. Ataxia telangiectasia mutated (ATM)-Chk2 and ATM- and Rad3-related (ATR)-Chk1 are two primary kinase signaling cascades activated in response to DNA damage. A growing body of evidence suggests that ATM and ATR phosphorylate KAP1 at Ser-824 in response to DNA damage and regulate KAP1-dependent chromatin condensation, DNA repair, and gene expression. Here, we show that, depending on the type of DNA damage that occurs, KAP1 Ser-473 can be phosphorylated by ATM-Chk2 or ATR-Chk1 kinases. Phosphorylation of KAP1 at Ser-473 attenuated its binding to the heterochromatin protein 1 family proteins and inhibited its transcriptional repression of KRAB-zinc finger protein (KRAB-ZFP) target genes. Moreover, KAP1 Ser-473 phosphorylation induced by DNA damage stimulated KAP1-E2F1 binding. Overexpression of heterochromatin protein 1 significantly inhibited E2F1-KAP1 binding. Elimination of KAP1 Ser-473 phosphorylation increased E2F1-targeted proapoptotic gene expression and E2F1-induced apoptosis in response to DNA damage. Furthermore, loss of phosphorylation of KAP1 Ser-473 led to less BRCA1 focus formation and slower kinetics of loss of γH2AX foci after DNA damage. KAP1 Ser-473 phosphorylation was required for efficient DNA repair and cell survival in response to DNA damage. Our studies reveal novel functions of KAP1 Ser-473 phosphorylation under stress.

Shoutai pills for threatened abortion: A protocol for systematic review and meta-analysis.

BACKGROUND: Threatened abortions are a serious health risk for women. Deferiprone tablets are commonly used in the treatment of clinical delivery. Traditional Chinese medicine, a characteristic medical system inherited for thousands of years, often applies Shoutai pills in the treatment of Threatened abortion and has achieved good results. This systematic review and meta-analysis aimed to evaluate the efficacy and safety of Shoutai pills combined with dedrogesterone tablets for the treatment of early preterm abortion. METHODS: Electronic searches of clinical randomized controlled trials in PubMed, Web of Science, MEDLINE, EMBASE, China National Knowledge Infrastructure, Wanfang database, and China Scientific Journal Database (VIP) were conducted. References to the included literature, gray literature in Open Grey, and other relevant literature such as clinical studies registered in ClinicalTrials.gov, were also manually searched. Relevant data were extracted, and a meta-analysis was performed using Reviewer Manager 5.4. RESULTS: The results of this study will be submitted to peer-reviewed journals. CONCLUSION: This study provides high-quality evidence on the efficacy and safety of Shoutai pills in combination with dedrogesterone tablets for the treatment of preterm abortion.

Compact Programmable Control of Protein Secretion in Mammalian Cells.

Synthetic biology currently holds immense potential to engineer the spatiotemporal control of intercellular signals for biomedicine. Programming behaviors using protein-based circuits has advantages over traditional gene circuits such as compact delivery and direct interactions with signaling proteins. Previously, we described a generalizable platform called RELEASE to enable the control of intercellular signaling through the proteolytic removal of ER-retention motifs compatible with pre-existing protease-based circuits. However, these tools lacked the ability to reliably program complex expression profiles and required numerous proteases, limiting delivery options. Here, we harness the recruitment and antagonistic behavior of endogenous 14-3-3 proteins to create RELEASE-NOT to turn off protein secretion in response to protease activity. By combining RELEASE and RELEASE-NOT, we establish a suite of protein-level processing and output modules called Compact RELEASE (compRELEASE). This innovation enables functions such as logic processing and analog signal filtering using a single input protease. Furthermore, we demonstrate the compactness of the post-translational design by using polycistronic single transcripts to engineer cells to control protein secretion via lentiviral integration and leverage mRNA delivery to selectively express cell surface proteins only in engineered cells harboring inducible proteases. CompRELEASE enables complex control of protein secretion and enhances the potential of synthetic protein circuits for therapeutic applications, while minimizing the overall genetic payload.

Modular, programmable RNA sensing using ADAR editing in living cells.

With the increasing availability of single-cell transcriptomes, RNA signatures offer a promising basis for targeting living cells. Molecular RNA sensors would enable the study of and therapeutic interventions for specific cell types/states in diverse contexts, particularly in human patients and non-model organisms. Here we describe a modular, programmable system for live RNA sensing using adenosine deaminases acting on RNA (RADAR). We validate, and then expand, our basic design, characterize its performance, and analyze its compatibility with human and mouse transcriptomes. We identify strategies to boost output levels and improve the dynamic range. Additionally, we show that RADAR enables compact AND logic. In addition to responding to transcript levels, RADAR can distinguish disease-relevant sequence alterations of transcript identities, such as point mutations and fusions. Finally, we demonstrate that RADAR is a self-contained system with the potential to function in diverse organisms.

DT-109 ameliorates nonalcoholic steatohepatitis in nonhuman primates.

Nonalcoholic steatohepatitis (NASH) prevalence is rising with no pharmacotherapy approved. A major hurdle in NASH drug development is the poor translatability of preclinical studies to safe/effective clinical outcomes, and recent failures highlight a need to identify new targetable pathways. Dysregulated glycine metabolism has emerged as a causative factor and therapeutic target in NASH. Here, we report that the tripeptide DT-109 (Gly-Gly-Leu) dose-dependently attenuates steatohepatitis and fibrosis in mice. To enhance the probability of successful translation, we developed a nonhuman primate model that histologically and transcriptionally mimics human NASH. Applying a multiomics approach combining transcriptomics, proteomics, metabolomics, and metagenomics, we found that DT-109 reverses hepatic steatosis and prevents fibrosis progression in nonhuman primates, not only by stimulating fatty acid degradation and glutathione formation, as found in mice, but also by modulating microbial bile acid metabolism. Our studies describe a highly translatable NASH model and highlight the need for clinical evaluation of DT-109.