Hydroxy-Safflower Yellow A Mitigates Vascular Remodeling in Rat Pulmonary Arterial Hypertension.

Purpose: The underlying causes of pulmonary arterial hypertension (PAH) often remain obscure. Addressing PAH with effective treatments presents a formidable challenge. Studies have shown that Hydroxysafflor yellow A (HSYA) has a potential role in PAH, While the mechanism underlies its protective role is still unclear. The study was conducted to investigate the potential mechanisms of the protective effects of HSYA. Methods: Using databases such as PharmMapper and GeneCards, we identified active components of HSYA and associated PAH targets, pinpointed intersecting genes, and constructed a protein-protein interaction (PPI) network. Core targets were singled out using Cytoscape for the development of a model illustrating drug-component-target-disease interactions. Intersection targets underwent analysis for Gene Ontology (GO) functions and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment. Selected components were then modeled for target interaction using Autodock and Pymol. In vivo validation in a monocrotaline-induced PAH (MCT-PAH) animal model was utilized to substantiate the predictions made by network pharmacology. Results: We associated HSYA with 113 targets, and PAH with 1737 targets, identifying 34 mutual targets for treatment by HSYA. HSYA predominantly affects 9 core targets. Molecular docking unveiled hydrogen bond interactions between HSYA and several PAH-related proteins such as ANXA5, EGFR, SRC, PPARG, PGR, and ESR1. Conclusion: Utilizing network pharmacology and molecular docking approaches, we investigated potential targets and relevant human disease pathways implicating HSYA in PAH therapy, such as the chemical carcinogenesis receptor activation pathway and the cancer pathway. Our findings were corroborated by the efficacious use of HSYA in an MCT-induced rat PAH model, confirming its therapeutic potential.

Resident operative time as an independent predictor of early post-operative cataract surgery outcomes and supervising attending surgeon impact: a retrospective case series.

BACKGROUND: The authors sought to determine if resident operative time in cataract extraction and intraocular lens insertion (CE/IOL) affects early visual outcomes and post-operative recovery. They further sought to investigate if attending surgeons can reduce resident operative time. METHODS: This retrospective, chart-review, case series at single Veterans Affairs Hospital (VA Tennessee Valley Healthcare System) studied resident cataract surgeries between March 1, 2018 and March 31, 2020. Following power analysis, 420 eyes of 400 patients from all resident cataract surgeries were included. Eyes with attending as primary surgeon, laser-assisted cataract surgery, or concurrent secondary procedures were excluded. Linear mixed effect models were used to study the association between operative time and visual outcomes while adjusting for covariates including cumulative dissipated energy, preoperative factors, and intraoperative complications. RESULTS: Longer operative time was statistically associated with worse post-operative-day 1 (POD1) pinhole visual acuity (PH-VA) adjusting for cumulative dissipated energy and other operative factors (p = 0.049). Although resident physicians were the primary surgeons, the operative times were different between the ten supervising attending surgeons in the study (p < 0.001). CONCLUSION: The results suggest that increased resident operative time is a significant, independent risk factor for decreased POD1 PH-VA. Increased resident operative time is not associated with worsened long term visual outcomes. Attending surgeons may be able to reduce resident operative time, which is associated with improved early visual outcomes.

A Pilot Nonrandomized Controlled Trial Examining the Use of Artificial Tears on the Radioactivity of Tears After Radioactive Iodine Treatment for Thyroid Cancer.

Background: Nasolacrimal duct obstruction (NLDO) is an adverse effect of high dose radioactive iodine (RAI) therapy for thyroid carcinoma. There are currently no established preventive measures. This study assesses whether preservative free artificial tears (PFATs) can decrease the 131I sodium iodide (131I) activity in the tears of patients following RAI therapy for thyroid carcinoma, and potentially serve as a preventive measure for RAI-associated NLDO. Methods: This non-randomized prospective pilot clinical trial recruited contact-lens wearing patients undergoing RAI therapy for thyroid cancer to self-administer PFATs into the right eye for four days starting on the day of RAI ingestion. Left eyes were the controls. While wearing contacts, patients self-administered PFATs per the following-Day 1: every 15 minutes for 2 hours, then every 30 minutes until bedtime, day 2: every hour for at least 12 hours, day 3: four times a day, and day 4: two times a day. Contact lenses were changed daily, and all lenses were collected one week later. Levels of 131I activity were measured by a well counter, decay-corrected, and converted to units of becquerel. Statistical analyses were performed to compare the 131I activities of the experimental and control eyes. Results: Sixteen eyes of eight patients treated with an average of 145.7 mCi (range 108-159) of 131I for papillary thyroid cancer were included. On day 1, artificial tears decreased the geometric mean 131I activity by 26% in the experimental eyes (p = 0.008). Artificial tears also decreased the geometric mean area under the curve over four days by 23% (p = 0.002). Conclusions: 131I is present in the tears following RAI therapy for thyroid carcinoma. Frequent PFATs starting on the day of RAI ingestion may decrease the level of 131I in the tears. This finding could have implications for lowering the risk of NLDO. Future multi-center clinical trials are needed to determine whether the use of artificial tears after RAI therapy may decrease the risk of NLDO. Clinical Trial Registration: NCT04327999.

Applicant Perceptions of In-Person versus Virtual Interview Format for Surgical Retina Fellowship.

Purpose This article compares applicants' perceptions of and experiences with virtual and in-person interviews for surgical retina fellowship. Methods A survey was distributed via email to all applicants of three vitreoretinal surgery fellowship programs for the 2021 to 2022 and 2022 to 2023 application cycles. Main Outcome Measures Participants were surveyed regarding cost; burden of scheduling; number of applications and interviews completed; ability to gain a true feel of the program, location, and preceptor; and number of work and surgical days missed. Results Of 151 applicants contacted, 36 completed the survey (23.8% response rate). Of the respondents, 25.0% attended only virtual interviews, 19.4% attended mostly virtual interviews, 30.6% attended mostly in-person interviews, and 25.0% attended half virtual and half in-person interviews. Average expenditure was significantly lower for applicants with mostly and completely virtual interviews compared with applicants with mostly in-person and half virtual, half in-person ( p < 0.001). Applicants with mostly virtual interviews reported a lower ability to gain a true perception of the program and the program location ( p = 0.003 and p < 0.001, respectively). There was no difference in burden of scheduling, number of interviews completed, or number of work and surgical days missed. When applicants were asked what type of interview format they would prefer if they could repeat the cycle, those who interviewed mostly in-person largely chose in-person as their preference (72.7%), while participants who interviewed mostly or completely virtually were evenly split between in-person, virtual, and hybrid ( p = 0.136). Conclusion As fellowship programs and institutions decide whether they will return to in-person interviews or maintain a virtual interview format in the long term, they must weigh the lower cost of virtual interviews with the improved ability to gain a more accurate perception of the program and location allowed by in-person interviews, as well as potentially greater satisfaction with the in-person format.

Hearing intervention for decreasing risk of developing dementia in elders with mild cognitive impairment: study protocol of a multicenter randomized controlled trial for Chinese Hearing Solution for Improvement of Cognition in Elders (CHOICE).

BACKGROUND: Age-related hearing loss (ARHL) signifies the bilateral, symmetrical, sensorineural hearing loss that commonly occurs in elderly individuals. Several studies have suggested a higher risk of dementia among patients diagnosed with ARHL. Although the precise causal association between ARHL and cognitive decline remains unclear, ARHL has been recognized as one of the most significant factors that can be modified to reduce the risk of developing dementia potentially. Mild cognitive impairment (MCI) typically serves as the initial stage in the transition from normal cognitive function to dementia. Consequently, the objective of our randomized controlled trial (RCT) is to further investigate whether the use of hearing aids can enhance cognitive function in older adults diagnosed with ARHL and MCI. METHODS AND DESIGN: This study is a parallel-arm, randomized controlled trial conducted at multiple centers in Shanghai, China. We aim to enlist a total of 688 older adults (age ≥ 60) diagnosed with moderate-to-severe ARHL and MCI from our four research centers. Participants will be assigned randomly to either the hearing aid fitting group or the health education group using block randomization with varying block sizes. Audiometry, cognitive function assessments, and other relevant data will be collected at baseline, as well as at 6, 12, and 24 months post-intervention by audiologists and trained researchers. The primary outcome of our study is the rate of progression to dementia among the two groups of participants. Additionally, various evaluations will be conducted to measure hearing improvement and changes in cognitive function. Apart from the final study results, we also plan to conduct an interim analysis using data from 12-month follow-up. DISCUSSION: In recent years, there has been a notable lack of randomized controlled trials (RCTs) investigating the possible causal relationship between hearing fitting and the improvement of cognitive function. Our findings may demonstrate that hearing rehabilitation can be a valuable tool in managing ARHL and preventing cognitive decline, which will contribute to the development of a comprehensive framework for the prevention and control of cognitive decline. TRIAL REGISTRATION: Chinese Clinical Trial Registry chictr.org.cn ChiCTR2000036139. Registered on 21 August 2020.

Trends in Imaging Utilization Among United States Medicare Beneficiaries and the Impact of the COVID-19 Pandemic.

This study characterizes trends in ophthalmic imaging volume and utilization in the United States among and assesses the potential impact of the COVID-19 pandemic using data from the Centers for Medicare and Medicaid Services. Utilization of macular optical coherence tomography (OCT), optic nerve OCT, and fundus photography steadily increased from 2013 to 2020 and was not impacted by the COVID-19 pandemic. At the same time, there was minimal adoption of anterior segment OCT and a decline in the utilization of dye-based angiography. Utilization patterns may be impacted by the advent of new technologies, role of the clinician, and alignment with treatment paradigms. [Ophthalmic Surg Lasers Imaging Retina 2023;54:661-665.].

Molecular dynamics simulations of electrochemical interfaces.

Molecular dynamics (MD) simulations have become a powerful tool for investigating electrical double layers (EDLs), which play a crucial role in various electrochemical devices. In this Review, we provide a comprehensive overview of the techniques used in MD simulations for EDL studies, with a particular focus on methods for describing electrode polarization, and examine the principle behind these methods and their varying applicability. The applications of these approaches in supercapacitors, capacitive deionization, batteries, and electric double-layer transistors are explored, highlighting recent advancements and insights in each field. Finally, we emphasize the challenges and potential directions for future developments in MD simulations of EDLs, such as considering movable electrodes, improving electrode property representation, incorporating chemical reactions, and enhancing computational efficiency to deepen our understanding of complex electrochemical processes and contribute to the progress in the field involving EDLs.

Diagnostic performance of RASSF1A and SHOX2 methylation combined with EGFR mutations for differentiation between small pulmonary nodules.

BACKGROUND AND AIM: Aberrant methylation of Ras association domain family 1, isoform A (RASSF1A), and short-stature homeobox gene 2 (SHOX2) promoters has been validated as a pair of valuable biomarkers for diagnosing early lung adenocarcinomas (LUADs). Epidermal growth factor receptor (EGFR) is the key driver mutation in lung carcinogenesis. This study aimed to investigate the aberrant promoter methylation of RASSF1A and SHOX2, and the genetic mutation of EGFR in 258 specimens of early LUADs. METHODS: We retrospectively selected 258 paraffin-embedded samples of pulmonary nodules measuring 2 cm or less in diameter and evaluated the diagnostic performance of individual biomarker assays and multiple panels between noninvasive (group 1) and invasive lesions (groups 2A and 2B). Then, we investigated the interaction between genetic and epigenetic alterations. RESULTS: The degree of RASSF1A and SHOX2 promoter methylation and EGFR mutation was significantly higher in invasive lesions than in noninvasive lesions. The three biomarkers distinguished between noninvasive and invasive lesions with reliable sensitivity and specificity: 60.9% sensitivity [95% confidence interval (CI) 52.41-68.78] and 80.0% specificity (95% CI 72.14-86.07). The novel panel biomarkers could further discriminate among three invasive pathological subtypes (area under the curve value > 0.6). The distribution of RASSF1A methylation and EGFR mutation was considerably exclusive in early LUAD (P = 0.002). CONCLUSION: DNA methylation of RASSF1A and SHOX2 is a pair of promising biomarkers, which may be used in combination with other driver alterations, such as EGFR mutation, to support the differential diagnosis of LUADs, especially for stage I.

Molecular Insights into Curvature Effects on the Capacitance of Electrical Double Layers in Tricationic Ionic Liquids with Carbon Nanotube Electrodes.

Ionic liquid (IL) electrolytes and carbon nanotube (CNT) electrodes have exhibited promising electrochemical performance in supercapacitors. Nevertheless, the adaptability of tricationic ILs (TILs) in CNT-based supercapacitors remains unknown. Herein, the performance of supercapacitors with (6,6), (8,8), (12,12), and (15,15) CNT electrodes in the TIL [C6(mim)3](Tf2N)3 was assessed via molecular dynamics simulations, paying attention to the electric double-layer (EDL) structures and the relations between the CNT curvature and capacitance. The results disclose that counterion and co-ion number densities near CNT electrodes have a marked reduction, compared with that of the graphene electrode. The capacitance of the EDL in the TIL increases significantly as the CNT curvature increases and the capacitance of the TIL/CNT systems is higher than that of the TIL/graphene system. Moreover, different EDL structures in the TIL and the monocationic IL (MIL) [C6mim][Tf2N] near CNT electrodes were revealed, showing higher-concentration anions [Tf2N]- at the CNT surfaces in the TIL. It is also verified that the TIL has a greater energy-storage ability under high potentials. Furthermore, the almost flat or weakly camel-like capacitance-voltage (C-V) curve of EDLs in the TIL turns into a bell shape in the MIL, because of the ion accumulation at the CNT surfaces and the associations between ions.

Metabolomics profiling of AKT/c-Met-induced hepatocellular carcinogenesis and the inhibitory effect of Cucurbitacin B in mice.

Hepatocellular carcinoma (HCC), the most common kind of liver cancer, accounts for the majority of liver cancer diagnoses and fatalities. Clinical aggressiveness, resistance to traditional therapy, and a high mortality rate are all features of this disease. Our previous studies have shown that co-activation of AKT and c-Met induces HCC development, which is the malignant biological feature of human HCC. Cucurbitacin B (CuB), a naturally occurring tetracyclic triterpenoid compound with potential antitumor activity. However, the metabolic mechanism of AKT/c-Met-induced Hepatocellular Carcinogenesis and CuB in HCC remains unclear. In this study, we established an HCC mouse model by hydrodynamically transfecting active AKT and c-Met proto-oncogenes. Based on the results of hematoxylin-eosin (H&E), oil red O (ORO) staining, and immunohistochemistry (IHC), HCC progression was divided into two stages: the early stage of HCC (3 weeks after AKT/c-Met injection) and the formative stage of HCC (6 weeks after AKT/c-Met injection), and the therapeutic effect of CuB was evaluated. Through UPLC-Q-TOF-MS/MS metabolomics, a total of 26 distinct metabolites were found in the early stage of HCC for serum samples, while in the formative stage of HCC, 36 distinct metabolites were found in serum samples, and 13 different metabolites were detected in liver samples. 33 metabolites in serum samples and 11 in live samples were affected by CuB administration. Additionally, metabolic pathways and western blotting analysis revealed that CuB influences lipid metabolism, amino acid metabolism, and glucose metabolism by altering the AKT/mTORC1 signaling pathway, hence decreasing tumor progression. This study provides a metabolic basis for the early diagnosis, therapy, and prognosis of HCC and the clinical application of CuB in HCC.

Mitigating Host Burden of Genetic Circuits by Engineering Autonegatively Regulated Parts and Improving Functional Prediction.

Mitigating unintended interferences between circuits and host cells is key to realize applications of synthetic regulatory systems both for bacteria and mammalian cells. Here, we demonstrated that growth burden and circuit dysregulation occurred in a concentration-dependent manner for specific transcription factors (CymR*/CymR) in E.coli, and direct negative feedback modules were able to control the concentration of CymR*/CymR, mitigate growth burden, and restore circuit functions. A quantitative design scheme was developed for circuits embedded with autorepression modules. Four key parameters were theoretically identified to determine the performance of autoregulated switches and were experimentally modified by fine-tuning promoter architectures and cooperativity. Using this strategy, we synthesized a number of switches and demonstrated its improvement of product titers and host growth controlling the complex deoxyviolacein biosynthesis pathway. Furthermore, we restored functions of a dysregulated multilayer NOR gate by integrating autorepression modules. Our work provides a blueprint for engineering host-adaptable synthetic systems.

Regulatory Mechanism of circEIF4G2 Targeting miR-26a in Acute Myocardial Infarction.

Background: Acute myocardial infarction (AMI) involves a series of complex cellular and molecular events, including circular RNAs (circRNAs), microRNAs (miRNAs) and other noncoding RNAs. Objective: In this study, the regulation mechanism of circEIF4G2 acting on miR-26a on HUVECs (Human Umbilical Vein Endothelial Cells) proliferation, cell cycle and angiogenesis ability was mainly explored in the vascular endothelial growth factor induced (VEGF-induced) angiogenesis model. Methods: VEGF induced HUVECs angiogenesis model was constructed, and the expression of circEIF4G2 and miR-26a in VEGF model was detected by qRT-PCR. When circEIF4G2 and miR-26a were knocked down or overexpressed in HUVECs, qRT-PCR was used to detect the expression of circEIF4G2 and miR-26a, CCK-8 was used to detect cell proliferation, flow cytometry was used to detect the cell cycle transition of HUVECs, and cell formation experiment was used to detect the ability of angiogenesis. MiRanda database and Targetscan predicted the binding site of circEIF4G2 and miR-26a, lucifase reporting assay and RNA pull down assay verified the interaction between circEIF4G2 and miR-26a. Results: After HUVECs were treated with VEGF, circEIF4G2 was significantly upregulated. After circEIF4G2 was knocked down, the proliferation and angiogenesis of HUVECs cells were decreased, and the process of cell cycle G0/G1 phase was blocked. The overexpression of miR-26a reduced the proliferation and angiogenesis of HUVECs cells and blocked the cell cycle progression of G0/G1 phase. Double lucifase reporter gene assay verified that circEIF4G2 could directly interact with miR-26a through the binding site, and RNA Pull down assay further verified the interaction between circEIF4G2 and miR-26a. When circEIF4G2 and miR-26a were knocked down simultaneously in HUVECs, it was found that knocking down miR-26a could reverse the inhibition of circEIF4G2 on cell proliferation, cycle and angiogenesis. Conclusion: In the VEGF model, circEIF4G2 was highly expressed and miR-26a was low expressed. MiR-26a regulates HUVECs proliferation, cycle and angiogenesis by targeting circEIF4G2.

CRISPR-Based Genetic Switches and Other Complex Circuits: Research and Application.

CRISPR-based enzymes have offered a unique capability to the design of genetic switches, with advantages in designability, modularity and orthogonality. CRISPR-based genetic switches operate on multiple levels of life, including transcription and translation. In both prokaryotic and eukaryotic cells, deactivated CRISPR endonuclease and endoribonuclease have served in genetic switches for activating or repressing gene expression, at both transcriptional and translational levels. With these genetic switches, more complex circuits have been assembled to achieve sophisticated functions including inducible switches, non-linear response and logical biocomputation. As more CRISPR enzymes continue to be excavated, CRISPR-based genetic switches will be used in a much wider range of applications.

[Research advance in multi-component pharmacokinetics of Chinese herbal extracts in recent five years].

The multi-component pharmacokinetic study of Chinese herbal extracts elaborates the in vivo processes,including absorption,distribution,metabolism,and excretion,of multiple bioactive components,which is of significance in revealing pharmacodynamic material basis of Chinese herbal medicine. In recent years,with the innovation in ideas,and development of techniques and methods on traditional Chinese medicine( TCM) research,the pharmacokinetic studies of Chinese herbal extracts were extensively performed,and notable progress has been made. This paper reviewed the advancement of multi-component pharmacokinetics of Chinese herbal extracts in recent five years from analysis technology of biological sample,the pharmacokinetic characteristics of Chinese herbal medicine with complex system,and the impacts of processing and pathological state on pharmacokinetics of Chinese herbal extracts,aiming to provide a reference for quality control,product development and rational medication of Chinese herbal extracts.

A Quantitative Serum Proteomic Analysis Helps to Explore the Comprehensive Mechanism and Identify Serum Biomarkers of Shengmai Injection's Effect on Isoproterenol-Induced Myocardial Ischemia in Rats.

Shengmai injection (SMI), a traditional Chinese medicine formula with the nature of multicomponent and multi-target, has been widely used in clinic for treating cardiovascular diseases in China; however, its comprehensive mechanism of action remains unclear. In this study, a TMT-based quantitative serum proteomics was performed to explore SMI's global mechanism and help identify serum biomarkers of its effect on isoproterenol (ISO)-induced myocardial ischemia rats. The results of TMT-based proteomic analysis identified 227, 100, and 228 differentially expressed proteins (DEPs) for the model compared to the control group, SMI pretreatment + model compared to the model group, and SMI pretreatment + model compared to the control group, respectively. Based on bioinformatics analyses of gene ontology (GO), KEGG pathways, and the protein-protein interaction (PPI) networks for the DEPs, it is concluded that the comprehensive mechanism of SMI's effect on ISO-induced myocardial ischemia injury includes regulation of energy metabolism, reducing endothelial cell permeability, regulation of vessel and cardiac contractility, anti-inflammation, and prevention of cell apoptosis. Furthermore, 10 common DEPs were found, and six of them were regulated in model vs. control group, while back-regulated in SMI pretreatment + model vs. model group. Among them, three functional proteins of glyceraldehyde-3-phosphate dehydrogenase (GAPDH), Fas apoptotic inhibitory molecule 3 (FAIM3), and uncharacterized protein (M0R5J4), which were verified by the PRM analysis, might be the potential serum biomarkers on SMI's effects. Overall, this serum proteomics of SMI not only provides insights into the comprehensive mechanism underlying SMI's effects on ischemic heart disease but also helps identify serum biomarkers for directing SMI's cardioprotective effects.

Association of intraoperative hypotension with acute kidney injury after liver resection surgery: an observational cohort study.

BACKGROUND: Acute kidney injury (AKI) is a major complication following liver resection. The aim of this study was to determine the risk factors for AKI after hepatic resection and whether intraoperative hypotension (IOH) was related to AKI. METHODS: Adult patients (≥ 18 years) undergoing liver resection between November 2017 and November 2019 at our hospital were retrospectively reviewed. AKI was defined as ≥50% increase in serum creatinine from baseline value within 48 h after surgery. IOH was defined as the lowest absolute mean arterial pressure (MAP) < 65 mmHg for more than 10 cumulative minutes during the surgery. Patients were divided into AKI group and non-AKI group, and were stratified by age ≥ 65 years. RESULTS: 796 patients who met our inclusion and exclusion criteria were analyzed. After multivariable regression analysis, the IOH (OR, 2.565; P = 0.009) and age ≥ 65 years (OR, 2.463; P = 0.008) were risk factors for AKI. The IOH (OR, 3.547; P = 0.012) and received red blood cell (OR, 3.032; P = 0.036) were risk factors of AKI in age ≥ 65 years patients. CONCLUSIONS: The IOH and age ≥ 65 years were risk factors for postoperative AKI, and IOH was associated with AKI in age ≥ 65 years patients following liver resection.

CRISPRi/dCpf1-mediated dynamic metabolic switch to enhance butenoic acid production in Escherichia coli.

Butenoic acid is a short-chain unsaturated fatty acid and important precursor for pharmaceutical and other applications. Heterologous thioesterases are able to convert a fatty acid biosynthesis intermediate in Escherichia coli to butenoic acid. In order to acquire high titer and yield of the product, dynamically switching the metabolic flux from fatty acid biosynthesis pathway to butenoic acid is critical after achieving enough cell mass of the host. A previous developed switch for butenoic acid fermentation is based on triclosan molecule as the FabI inhibitor in the fatty acid biosynthesis cycle. However, triclosan is toxic to human, which may limit its pharmaceutical application. Alternatively, we here purposed a nontoxic switch of carbon flux by harnessing recently developed CRISPR interference (CRISPRi) approach. In our work, we constructed a CRISPRi/dCpf1-mediated dynamic metabolic switch to separate the host growth and production phase via switching the expression of the fabI gene in fatty acid biosynthesis pathway. After optimizing the programmable targets, the CRISPRi-based switch boosted the titer of butenoic acid by 6-fold (1.41 g/L) in fed-batch fermentation. Our work supported that the CRISPRi/dCpf1 switch could replace triclosan-based switch as a nontoxic switch for butenoic acid production, and outcompeted the later switch in the biomass accumulation of the host cell. Moreover, the CRISPRi/dCpf1 system was integrated into the chromosome of the host to improve its genetic stability for long-term fermentation and other applications.Key Points• A programmable metabolic switch was developed to replace the toxic chemical switch to separate the growth phase and production phase of the butenoic acid.• The programmable CRISPRi/dCpf1 switch was efficiently and stably integrated into the host genome to increase their genetic stability during fermentation.• The optimized metabolic switch simultaneously increased the host biomass and butenoic acid titer, and solved the paradox of the competition between growth and production.

Engineering of a genetic circuit with regulatable multistability.

Synthetic biologists are dedicated to designing genetic systems from the bottom up to understand how living systems work. To date, a variety of genetic circuits exhibiting bistability have been designed, greatly expanding our understanding of the biological multistability in natural systems. However, the study of more complex forms of biological multistability using synthetic methods is still limited. In this report, we describe the engineering of a genetic circuit with regulatable multistability. A novel genetic toggle switch exhibiting inducible bistability and a self-activation circuit were individually designed and characterized, after which they were assembled to create a circuit that presents tristability. In bacteria, this synthetic circuit enables cells to differentiate spontaneously into three different states of gene expression. Moreover, the multistability of the circuit can be modulated by external inputs. This work provides a synthetic biology framework for the study of biological multistability and may help to understand natural multistability phenomena.

[Advances in synthetic physiology of artificial genetic parts].

Artificial genetic parts should be modularized and can be predictably scaled up via assembly or reused in other contexts. Under intracellular physiological conditions, however, the functions of the assembled parts are severely impeded by multi-level physiological interference, i.e., most artificial assembled systems cannot be functional as predicted. Here we proposed a concept of synthetic physiology, defining it as the branch of synthetic biology to investigate and control interferences between artificial genetic parts and intracellular physiological system. Under such framework, we describe the part-host interactions and review the methods and strategies used to characterize and address these interactions.