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Abstract 3-Hydroxybutyrate (3HB) is a small ketone body molecule produced endogenously by the body in the liver. Previous studies have shown that 3HB can reduce blood glucose level in type 2 diabetic (T2D) patients. However, there is no systematic study and clear mechanism to evaluate and explain the hypoglycemic effect of 3HB. Here we demonstrate that 3HB reduces fasting blood glucose level, improves glucose tolerance, and ameliorates insulin resistance in type 2 diabetic mice through hydroxycarboxylic acid receptor 2 (HCAR2). Mechanistically, 3HB increases intracellular calcium ion (Ca2+) levels by activating HCAR2, thereby stimulating adenylate cyclase (AC) to increase cyclic adenosine monophosphate (cAMP) concentration, and then activating protein kinase A (PKA). Activated PKA inhibits Raf1 proto-oncogene serine/threonine-protein kinase (Raf1) activity, resulting in a decrease in extracellular signal-regulated kinases 1/2 (ERK1/2) activity and ultimately inhibiting peroxisome proliferator-activated receptor γ (PPARγ) Ser273 phosphorylation in adipocytes. Inhibition of PPARγ Ser273 phosphorylation by 3HB altered the expression of PPARγ regulated genes and reduced insulin resistance. Collectively, 3HB ameliorates insulin resistance in type 2 diabetic mice through a pathway of HCAR2/Ca2+/cAMP/PKA/Raf1/ERK1/2/PPARγ.

Abstract Synthetic biology aims to design or assemble existing bioparts or bio-components for useful bioproperties. During the past decades, progresses have been made to build delicate biocircuits, standardized biological building blocks and to develop various genomic/metabolic engineering tools and approaches. Medical and pharmaceutical demands have also pushed the development of synthetic biology, including integration of heterologous pathways into designer cells to efficiently produce medical agents, enhanced yields of natural products in cell growth media to equal or higher than that of the extracts from plants or fungi, constructions of novel genetic circuits for tumor targeting, controllable releases of therapeutic agents in response to specific biomarkers to fight diseases such as diabetes and cancers. Besides, new strategies are developed to treat complex immune diseases, infectious diseases and metabolic disorders that are hard to cure via traditional approaches. In general, synthetic biology brings new capabilities to medical and pharmaceutical researches. This review summarizes the timeline of synthetic biology developments, the past and present of synthetic biology for microbial productions of pharmaceutics, engineered cells equipped with synthetic DNA circuits for diagnosis and therapies, live and auto-assemblied biomaterials for medical treatments, cell-free synthetic biology in medical and pharmaceutical fields, and DNA engineering approaches with potentials for biomedical applications.

Abstract Objective: The impact of the dietary potential inflammatory effect on diabetic kidney disease (DKD) has not been adequately investigated. The present study aimed to explore the association between dietary inflammatory index (DII) and DKD in US adults. Design: This is a cross-sectional study. Setting: Data from the National Health and Nutrition Examination Survey (2007–2016) were used. DII was calculated from 24-h dietary recall interviews. DKD was defined as diabetes with albuminuria, impaired glomerular filtration rate or both. Logistic regression and restricted cubic spline models were adopted to evaluate the associations. Participants: Data from the National Health and Nutrition Examination Survey (2007–2016) were used, which can provide the information of participants. Results: Four thousand two-hundred and sixty-four participants were included in this study. The adjusted OR of DKD was 1·04 (95 % CI 0·81, 1·36) for quartile 2, 1·24 (95 % CI 0·97, 1·59) for quartile 3 and 1·64 (95 % CI 1·24, 2·17) for quartile 4, respectively, compared with the quartile 1 of DII. A linear dose–response pattern was observed between DII and DKD (P nonlinearity = 0·73). In the stratified analyses, the OR for quartile 4 of DII were significant among adults with higher educational level (OR 1·83, 95 % CI 1·26, 2·66) and overweight or obese participants (OR 1·67, 95 % CI 1·23, 2·28), but not among the corresponding another subgroup. The interaction effects between DII and stratified factors on DKD were not statistically significant (all P values for interactions were >0·05). Conclusions: Our findings suggest that a pro-inflammatory diet, shown by a higher DII score, is associated with increased odd of DKD.

Abstract Background Selectively targeting leukemia stem cells (LSCs) is a promising approach in treating acute myeloid leukemia (AML), for which identification of such therapeutic targets is critical. Increasing lines of evidence indicate that FBXO22 plays a critical role in solid tumor development and therapy response. However, its potential roles in leukemogenesis remain largely unknown. Methods We established a mixed lineage leukemia (MLL)-AF9-induced AML model with hematopoietic cell-specific FBXO22 knockout mice to elucidate the role of FBXO22 in AML progression and LSCs regulation, including self-renewal, cell cycle, apoptosis and survival analysis. Immunoprecipitation combined with liquid chromatography-tandem mass spectrometry analysis, Western blotting and rescue experiments were performed to study the mechanisms underlying the oncogenic role of FBXO22. Results FBXO22 was highly expressed in AML, especially in MLL-rearranged (MLLr) AML. Upon FBXO22 knockdown, human MLLr leukemia cells presented markedly increased apoptosis. Although conditional deletion of Fbxo22 in hematopoietic cells did not significantly affect the function of hematopoietic stem cells, MLL-AF9-induced leukemogenesis was dramatically abrogated upon Fbxo22 deletion, together with remarkably reduced LSCs after serial transplantations. Mechanistically, FBXO22 promoted degradation of BACH1 in MLLr AML cells, and overexpression of BACH1 suppressed MLLr AML progression. In line with this, heterozygous deletion of BACH1 significantly reversed delayed leukemogenesis in Fbxo22-deficient mice. Conclusions FBXO22 promotes MLLr AML progression by targeting BACH1 and targeting FBXO22 might be an ideal strategy to eradicate LSCs without influencing normal hematopoiesis.

Abstract Halomonas bluephagenesis TD1.0 was engineered to produce the biofuel propane, bioplastic poly‐3‐hydroxybutyrate (PHB), and biochemicals mandelate and hydroxymandelate in a single, semi‐continuous batch fermentation under non‐sterile conditions. Multi‐product separation was achieved by segregation of the headspace gas (propane), fermentation broth ([hydroxy]mandelate) and cellular biomass (PHB). Engineering was performed by incorporating the genes encoding fatty acid photodecarboxylase (CvFAP) and hydroxymandelic acid synthase (SyHMAS) into a H. bluephagenesis hmgCAB cassette knockout to channel flux towards (hydroxy)mandelate. Design of Experiment strategies were coupled with fermentation trials to simultaneously optimize each product. Propane and mandelate titres were the highest reported for H. bluephagenesis (62 g/gDCW and 71 ± 10 mg/L respectively) with PHB titres (69% g/gDCW) comparable to other published studies. This proof‐of‐concept achievement of four easily separated products within one fermentation is a novel achievement probing the versatility of biotechnology, further elevating H. bluephagenesis as a Next Generation Industrial Biotechnology (NGIB) chassis by producing highly valued products at a reduced cost.

Abstract The bioeconomy drives the development of life science and biotechnology as a blueprint for the future development of human society, and offers a cross‐cutting perspective on the societal transformation towards long‐term sustainability and the transition away from the non‐renewable economy. Moreover, the sustainable bioeconomy strategies are consistent with the United Nation's (UN) Sustainable Development Goals (SDG) and are becoming the centre of the achievement for SDG. The Chinese ‘14th Five‐Year Plan for Bioeconomy Development’ (2021–2025), including the development goals of China's bioeconomy containing biomedicine, agriculture, bio‐manufacturing and bio‐security as a strategic priority, is discussed. The plan offers three pathways to improve bioeconomy, including technological innovation, industrialisation and policy supports. Finally, it concludes China's first bioeconomy development plan as a success, suggesting the key role of industrial biotechnology in bioeconomy.

BackgroundDespite increasing evidence that has shown the association of ultra-processed foods (UPFs) with cancer risk, the results remain inconclusive. We, therefore, conducted the meta-analysis to clarify the association by including recently published studies.MethodsA comprehensive search was conducted in PubMed, Embase, and Web of Science to identify all relevant studies from inception to January 2023. To pool data, fixed-effects or random-effects models were used where appropriate. Subgroup analyses, sensitivity analyses, and publication bias tests were performed.ResultsA total of 13 studies (4 cohort studies and 9 case–control studies) were included in the analysis, with a total of 625,738 participants. The highest UPFs consumption was associated with increased risk of colorectal cancer (OR = 1.23, 95% CI: 1.10–1.38), colon cancer (OR = 1.25, 95% CI: 1.14–1.36), and breast cancer (OR = 1.10, 95% CI: 1.00–1.20) but not rectal cancer (OR = 1.18, 95% CI: 0.97–1.43) and prostate cancer (OR = 1.03, 95% CI: 0.93–1.12). In addition, the subgroup analyses showed that a positive association between UPFs consumption and colorectal cancer was observed among men (OR = 1.31, 95% CI: 1.15–1.50), whereas no significant association was observed among women (OR = 1.10, 95% CI: 0.94–1.29).ConclusionThe present meta-analysis suggests that high UPFs consumption is associated with a significantly increased risk of certain site-specific cancers, especially the digestive tract and some hormone-related cancers. However, further rigorously designed prospective and experimental studies are needed to better understand causal pathways.

Measurement(s) Genome • Proteomic Profile Technology Type(s) PacBio Sequel System • nanoflow liquid chromatography-electrospray ionisation mass spectrometry Sample Characteristic - Organism Halomonas sp. TD01

Abstract Background Muscle atrophy is an increasingly global health problem affecting millions, there is a lack of clinical drugs or effective therapy. Excessive loss of muscle mass is the typical characteristic of muscle atrophy, manifesting as muscle weakness accompanied by impaired metabolism of protein and nucleotide. (D)-3-hydroxybutyrate (3HB), one of the main components of the ketone body, has been reported to be effective for the obvious hemodynamic effects in atrophic cardiomyocytes and exerts beneficial metabolic reprogramming effects in healthy muscle. This study aims to exploit how the 3HB exerts therapeutic effects for treating muscle atrophy induced by hindlimb unloaded mice. Results Anabolism/catabolism balance of muscle protein was maintained with 3HB via the Akt/FoxO3a and the mTOR/4E-BP1 pathways; protein homeostasis of 3HB regulation includes pathways of ubiquitin–proteasomal, autophagic-lysosomal, responses of unfolded-proteins, heat shock and anti-oxidation. Metabolomic analysis revealed the effect of 3HB decreased purine degradation and reduced the uric acid in atrophied muscles; enhanced utilization from glutamine to glutamate also provides evidence for the promotion of 3HB during the synthesis of proteins and nucleotides. Conclusions 3HB significantly inhibits the loss of muscle weights, myofiber sizes and myofiber diameters in hindlimb unloaded mouse model; it facilitates positive balance of proteins and nucleotides with enhanced accumulation of glutamate and decreased uric acid in wasting muscles, revealing effectiveness for treating muscle atrophy. Graphical Abstract

CRISPR/Cas9 editing of a PHB-producing H. bluephagenesis strain is used to delete the redundant synthesis pathways of flagella and EPSs, allowing for enhanced self-flocculation, less carbon and energy requirement for metabolic processes and feasible electrotransformation.

Abstract PTENα and PTENβ (PTENα/β), two long translational variants of phosphatase and tensin homolog on chromosome 10 (PTEN), exert distinct roles from canonical PTEN, including promoting carcinogenesis and accelerating immune-resistant cancer progression. However, their roles in carcinogenesis remain greatly unknown. Herein, we report that, after secreting into the extracellular space, PTENα/β proteins are efficiently cleaved into a short N-terminal and a long C-terminal fragment by the proprotein convertase Furin at a polyarginine stretch in their N-terminal extensions. Although secreted PTENα/β and their cleaved fragment cannot enter cells, treatment of the purified C-terminal fragment but not cleavage-resistant mutants of PTENα exerts a tumor-suppressive role in vivo. As a result, overexpression of cleavage-resistant PTENα mutants manifest a tumor-promoting role more profound than that of wild-type PTENα. In line with these, the C-terminal fragment is significantly downregulated in liver cancer tissues compared to paired normal tissues, which is consistent with the downregulated expression of Furin. Collectively, we show that extracellular PTENα/β present opposite effects on carcinogenesis from intracellular PTENα/β, and propose that the tumor-suppressive C-terminal fragment of PTENα/β might be used as exogenous agent to treat cancer.

Multi-omic data mining has the potential to revolutionize synthetic biology especially in non-model organisms that have not been extensively studied. However, tangible engineering direction from computational analysis remains elusive due to the interpretability of large datasets and the difficulty in analysis for non-experts. New omics data are generated faster than our ability to use and analyse results effectively, resulting in strain development that proceeds through classic methods of trial-and-error without insight into complex cell dynamics. Here we introduce a user-friendly, interactive website hosting multi-omics data. Importantly, this new platform allows non-experts to explore questions in an industrially important chassis whose cellular dynamics are still largely unknown. The web platform contains a complete KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway enrichment analysis derived from principal components analysis, an interactive bio-cluster heatmap analysis of genes, and the Halomonas TD1.0 genome-scale metabolic (GEM) model. As a case study of the effectiveness of this platform, we applied unsupervised machine learning to determine key differences between Halomonas bluephagenesis TD1.0 cultivated under varied conditions. Specifically, cell motility and flagella apparatus are identified to drive energy expenditure usage at different osmolarities, and predictions were verified experimentally using microscopy and fluorescence labelled flagella staining. As more omics projects are completed, this landing page will facilitate exploration and targeted engineering efforts of the robust, industrial chassis H bluephagenesis for researchers without extensive bioinformatics background.

Summary Bacterial outer membrane (OM) is a self‐protective and permeable barrier, while having many non‐negligible negative effects in industrial biotechnology. Our previous studies revealed enhanced properties of Halomonas bluephagenesis based on positive cellular properties by OM defects. This study further expands the OM defect on membrane compactness by completely deleting two secondary acyltransferases for lipid A modification in H. bluephagenesis, LpxL and LpxM, and found more significant advantages than that of the previous lpxL mutant. Deletions on LpxL and LpxM accelerated poly(3‐hydroxybutyrate) (PHB) production by H. bluephagenesis WZY229, leading to a 37% increase in PHB accumulation and 84‐folds reduced endotoxin production. Enhanced membrane permeability accelerates the diffusion of γ‐butyrolactone, allowing H. bluephagenesis WZY254 derived from H. bluephagenesis WZY229 to produce 82wt% poly(3‐hydroxybutyrate‐co‐23mol%4‐hydroxybutyrate) (P(3HB‐co‐23mol%4HB)) in shake flasks, showing increases of 102% and 307% in P(3HB‐co‐4HB) production and 4HB accumulation, respectively. The 4HB molar fraction in copolymer can be elevated to 32 mol% in the presence of more γ‐butyrolactone. In a 7‐l bioreactor fed‐batch fermentation, H. bluephagenesis WZY254 supported a 84 g l−1 dry cell mass with 81wt% P(3HB‐co‐26mol%4HB), increasing 136% in 4HB molar fraction. This study further demonstrated that OM defects generate a hyperproduction strain for high 4HB containing copolymers.

Summary Polyhydroxyalkanoates (PHA) are a promising and sustainable alternative to the petroleum‐based synthetic plastics. Regulation of PHA synthesis is receiving considerable importance as engineering the regulatory factors might help developing strains with improved PHA‐producing abilities. PHA synthesis is dedicatedly regulated by a number of regulatory networks. They tightly control the PHA content, granule size and their distribution in cells. Most PHA‐accumulating microorganisms have multiple regulatory networks that impart a combined effect on PHA metabolism. Among them, several factors ranging from global to specific regulators, have been identified and characterized till now. This review is an attempt to categorically summarize the diverse regulatory circuits that operate in some important PHA‐producing microorganisms. However, in several organisms, the detailed mechanisms involved in the regulation of PHA synthesis is not well‐explored and hence further research is needed. The information presented in this review might help researcher to identify the prevailing research gaps in PHA regulation.

Platelets have been shown to alter immune cell function but it is not clear if this includes autoimmunity. Here the authors show that phosphatase and tensin homolog (PTEN) deficient platelets promote autoimmunity in mouse models through excessive activation of TFH cells and systemic autoimmune pathology.

The gut microbiota was emerging as critical regulatory elements in shaping the outcome of cancer immunotherapy. However, the underlying mechanisms by which the gut commensal species enhance antitumor immunity remain largely unexplored. Here, we show that the gut microbiota from healthy individuals conferred considerable sensitivity to anti-PD-1 in the colorectal cancer (CRC) tumor-bearing mice, whereas gut microbiota from CRC patients failed to do so. By 16S rRNA gene sequencing, we identified Lactobacillus that was significantly increased in the mice with good response to anti-PD-1, and significantly correlated with anti-tumor immunity. After a series of screening, we isolated a novel Lacticaseibacillus strain, named L. paracasei sh2020. L. paracasei sh2020 showed the most notable anti-tumor immunity in the mice with gut dysbiosis. Mechanistically, the antitumor immune response elicited by L. paracasei sh2020 was dependent on CD8+ T cell. In vitro and in vivo studies revealed that L. paracasei sh2020 stimulation triggered the upregulated expression of CXCL10 in the tumors and subsequently enhanced CD8+ T cell recruitment. Meanwhile, the modulation of gut microbiota caused by L. paracasei sh2020 enhanced its antitumor effect and gut barrier function. Overall, our study offered novel insights into the mechanism by which gut microbiota shaped the outcome of cancer immunotherapy and, more importantly, the novel strain L. paracasei sh2020 might serve as an easy and effective way to promote anti-PD-1 effect in clinical practice.

Met1-linked linear ubiquitination (M1-Ubi) is catalyzed by linear ubiquitin chain assembly complex (LUBAC). Here the authors show that Ago2 protein is M1-Ubi modified by LUBAC complex under hypoxia condition leading to less association of miRNA target mRNAs to Ago2 protein and de-repression of miRNA targets.

BackgroundLow klotho is associated with aging-related traits. However, no study has assessed the association between klotho and oral health in a large sample of population. This study aimed to explore the association between serum α-klotho and oral health in US Adults.MethodsData were from the National Health and Nutrition Examination Survey. Oral health parameters included periodontitis, self-rated oral health, and tooth loss. Logistic regression and restricted cubic spline models were adopted to evaluate the associations.ResultsA total of 6187 participants were included in the study. The median of the α-klotho level was 815.2 pg/mL. Serum α-Klotho was significantly lower in participants with poor oral health (all P

3-Hydroxypropionic acid (3HP) is an important platform chemical. Here, the authors engineer Halomonas bluephagenesis by deleting newly identified degradation pathway and balancing redox state to achieve high level production of 3HP and its copolymer under open and unsterile conditions.

Genetic circuits can be built with bifunctional dynamic regulation of gene expression. Here the authors design a thermosensitive switch for spatial and temporal control of colony pattern, cell shape and polymer production.

Summary Microbial fermentations produce chemicals, materials, biofuels, foods and medicines for many years. The processes are less competitive compared to chemical industries. To increase its competitiveness, technologies must be developed to address the following issues including fresh water shortage, heavy energy consumption, microbial contaminations, complexity of sterile operations, poor oxygen utilization in the cultures, food‐related ingredients as substrates, low substrate to product conversion efficiency, difficult cells and broth separation, large amount of wastewater, discontinuous processes, heavy labour involvements and expensive bioreactors. Future industrial fermentations should be more effective with the above issues reasonably addressed. Recently, extremophilic bacteria have well addressed the above issues for future fermentation.

Resistance to tyrosine kinase inhibitors (TKI) is a limitation to their use in treating chronic myelogenous leukemia (CML). Here, the authors show that targeting the ubiquitin peptidase USP47 overcomes TKI resistance and eliminates leukaemia stem/progenitor cells in primary and xenograft CML murine models.

Objective To summarize and analyze the data of postural balance and gait disorders in patients with Meige's syndrome (MS) who underwent subthalamic nucleus deep brain stimulation (STN ⁃ DBS). Methods The study included 14 patients with MS who underwent bilateral STN⁃DBS surgery from July 2015 to September 2019 and developed postural balance and gait disorders. Burke⁃Fahn⁃ Marsden Dystonia Rating Scale (BFMDRS) and Tinetti Balance and Gait Analysis (TBGA) were used to assess the degrees of dystonia and balance, and gait disorders at the time of preoperative and final follow ⁃ up, respectively. Results The STN⁃DBS stimulation mode was unipolar in all 14 patients, and all showed some degrees of postural balance and gait disorders. The mean follow⁃up time was (28.36 ± 9.52) months. At the last follow⁃up, the overall improvement in BFMDRS score was (79.57 ± 22.21)%, among which the improvement rate of the motor score was (78.68 ± 19.91)% and the dysfunction score was (72.99 ± 46.54)%. The total score of BFMDRS (Z = ⁃ 4.055, P = 0.000) and the motor score (Z = ⁃ 3.919, P = 0.000) were lower than those before operation. The deterioration rate of TBGA was (28.61 ± 9.66)% , including of balance score (22.05 ± 10.32)% and gait score (37.39 ± 9.79)%. Total TBGA score (Z = ⁃ 4.658, P = 0.000), balance score (Z = ⁃ 3.325, P = 0.001) and gait score (Z = ⁃ 3.324, P = 0.001) were all lower than those before operation. By adjusting program⁃controlled parameters or changing stimulation contacts during the follow⁃up period, balance and gait disorder were improved obviously in 6 patients, however, 8 patients' symptoms were not improved well. Conclusions Patients with MS may experience a certain percentage of balance and gait disorders after treatment with STN⁃DBS. By adjusting the stimulation contact and changing the program⁃controlled parameters, it is only effective for some patients. Whether the other stimulation modes (bipolar stimulation, frequency conversion stimulation, cyclic stimulation, etc.) are effective or not remains to be studied. DOI：10.3969/j.issn.1672⁃6731.2020.12.007

3-hydroxybutyrate (3OHB) has been proved to act as a neuroprotective molecule in multiple neurodegenerative diseases. Here, we employed a quantitative proteomics approach to assess the changes of the global protein expression pattern of neural cells upon 3OHB administration. In combination with a disease-related, protein-protein interaction network we pinpointed a hub marker, histone lysine 27 trimethylation, which is one of the key epigenetic markers in multiple neurodegenerative diseases. Integrative analysis of transcriptomic and epigenomic datasets highlighted the involvement of bivalent transcription factors in 3OHB-mediated disease protection and its alteration of neuronal development processes. Transcriptomic profiling revealed that 3OHB impaired the fate decision process of neural precursor cells by repressing differentiation and promoting proliferation. Our study provides a new mechanism of 3OHB’s neuroprotective effect, in which chromatin bivalency is sensitive to 3OHB alteration and drives its neuroprotective function both in neurodegenerative diseases and in neural development processes.

BackgroundSarcopenia is a major public health problem. Depressive symptoms and dietary inflammatory potential play important roles in the development of sarcopenia. We aimed to disentangle the relationships between depressive symptoms, dietary inflammatory potential, and sarcopenia.MethodsA total of 6,082 participants from the National Health and Nutrition Examination Survey (NHANES) were included in the analyses. Sarcopenia was defined according to the Foundation for the National Institutes for Health (FNIH) criteria. The Depressive symptoms were assessed using the nine-item Patient Health Questionnaire (PHQ-9). Dietary Inflammatory Index (DII) was calculated based on 24-h dietary recall interview. Two sets of mediation models were constructed separately.ResultsDepressive symptoms and DII were associated with sarcopenia, with odds ratios [ORs] (95% CIs) 2.54 (1.27, 5.13) and 1.17 (1.00, 1.37), respectively. DII score mediated the association of depressive symptoms with low muscle mass, explaining a total of 10.53% of the association (indirect effect = 0.004). Depressive symptoms had a significant mediating effects on the association between DII with low muscle mass, explaining a total of 12.50% of the association (indirect effect = 0.001).ConclusionsOur findings suggested that both depressive symptoms and dietary inflammatory potential had direct effects, and indirect effects on low muscle mass, handgrip strength, muscle mass, through each other. It provides important insights into integrated nutritional and psychological intervention strategies in preventing sarcopenia.

Halomonas bluephagenesis is a halophilic platform bacterium for next generation industrial biotechnology. Here, the authors employ a stimulus response-based flux-tuning method for coproduction of bioplastic PHB and ectoine under open unsterile and continuous growth conditions.

Loss of nuclear PTEN is associated with aggressive cancers. Here the authors show that nuclear PTEN is more susceptible to ubiquitin-mediated proteasomal degradation than cytoplasmic PTEN, and identify FBXO22 ubiquitinates and degrades nuclear PTEN to promote tumorigenesis.

Polyhydroxyalkanoates (PHA) have been produced by several bacteria as bioplastics in industrial scales. PHA commercialization has been challenging due to its complexity and the associated high cost together with instabilities on molecular weights (Mw) and structures, thus instability on thermo- and mechanical properties. PHA high production cost is related to complicated bioprocessing associated with sterilization, low conversion of carbon substrates to PHA products, and poor growth of microorganisms as well as complicated downstream separation. To reduce complexity of PHA production, robust microorganisms that are contamination resistant bacteria have been targeted especially extremophiles, developments of engineering approaches for extremophiles especially Halomonas spp. for better PHA production have been successfully conducted and termed as “next generation industrial biotechnology” (NGIB). Diverse PHA can also be produced by engineering Halomonas or Pseudomonas spp. This review introduces recent advances on engineering bacteria for enhanced PHA biosynthesis and diversity. Keywords: PHB, Polyhydroxyalkanoates, Extremophiles, Halophiles, Next generation industrial biotechnology, NGIB, Metabolic engineering, Pathway engineering, Morphology engineering, Functional polymers

Bio-based flame-retardant agents and layer-by-layer assembly have attracted a great deal of attention in the flame-retardant fields of textiles, composites and polymeric materials. In this study, the electrostatic layer-by-layer assembly of chitosan and sodium phytate on silk fabric was carried out using a padding technique. The effects of the concentration and assembled bilayer of chitosan and sodium phytate on the weight gain, flammability, surface morphology, whiteness, stiff ness, lustre, tensile strength, and washing durability of silk fabric were studied, and the heat release, thermal stability and flame-retardant mechanism of the coated fabric were analysed. The results revealed that at 10 to 15 assembled bilayers, the coated fabrics exhibited high limiting oxygen indexes and passed the vertical burning test, and their good flame retardancy was maintained even after 15 washing cycles. Moreover, the coated fabrics exhibited a significant decrease in peak the heat release rate and a strong charring ability at high temperatures. The chitosan and sodium phytate system acted as flame retardants in the condensed phase. Given the high weight gain of silk fabric, the layer-by-layer assembly of chitosan and sodium phytate using a padding technique was more applicable to the flame-retardant treatment of furnishing fabrics.

Objective: We aimed to systematically evaluate the association between Dietary Inflammatory Index (DII) and mental health.Methods: We searched PubMed, Embase, and Web of Science from their inception to December 31, 2020. Categorical meta-analysis and dose–response meta-analysis were performed to evaluate the association between DII and mental health.Results: A total of 16 studies were included in this meta-analysis. Compared with the lowest DII category, the highest category was significantly associated with a variety of mental health outcomes, with the following pooled odds ratios (ORs) and 95% confidence intervals (95% CIs): 1.28 (1.17–1.39) for symptoms of depression, 1.27 (1.08–1.49) for symptoms of anxiety, 1.85 (1.43–2.40) for distress, and 4.27 (1.27–14.35) for schizophrenia. Furthermore, there was a linear dose–response relationship between DII and symptoms of depression in that a 1-unit increment in DII was associated with an increased risk of 6% for symptoms of depression (OR: 1.06, 95% CI: 1.03–1.19).Conclusion: The present study indicates that more pro-inflammatory diet, as estimated by the higher DII score, is associated with symptoms of mental disorder. It may be of clinical and public health significance regarding the development of novel nutritional psychiatry approaches to promote good mental health.

Abstract Atherosclerosis is a chronic inflammatory disease that can cause acute cardiovascular events. Activation of the NOD‐like receptor family, pyrin domain containing protein 3 (NLRP3) inflammasome enhances atherogenesis, which links lipid metabolism to sterile inflammation. This study examines the impact of an endogenous metabolite, namely ketone body 3‐hydroxybutyrate (3‐HB), on a mouse model of atherosclerosis. It is found that daily oral administration of 3‐HB can significantly ameliorate atherosclerosis. Mechanistically, 3‐HB is found to reduce the M1 macrophage proportion and promote cholesterol efflux by acting on macrophages through its receptor G‐protein‐coupled receptor 109a (Gpr109a). 3‐HB–Gpr109a signaling promotes extracellular calcium (Ca2+) influx. The elevation of intracellular Ca2+ level reduces the release of Ca2+ from the endothelium reticulum (ER) to mitochondria, thus inhibits ER stress triggered by ER Ca2+ store depletion. As NLRP3 inflammasome can be activated by ER stress, 3‐HB can inhibit the activation of NLRP3 inflammasome, which triggers the increase of M1 macrophage proportion and the inhibition of cholesterol efflux. It is concluded that daily nutritional supplementation of 3‐HB attenuates atherosclerosis in mice.

The global pandemic of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is an unprecedented threat to the human health. A close association of the digestive tract is implied by the high frequency of gastrointestinal syndromes among COVID-19 patients. A better understanding of the role of intestinal microenvironment in COVID-19 immunopathology will be helpful to improve the control of COVID-19 associated morbidity and mortality. This review summarizes the immune responses associated with the severity of COVID-19, the current evidence of SARS-CoV-2 intestinal tropism, and the potential involvement of gut microenvironment in COVID-19 severity. Additionally, we discuss the therapeutic potential of probiotics as an alternative medicine to prevent or alleviate severe COVID-19 outcome.

Cytoplasmic PTEN is a tumor suppressor that antagonises PI3K signalling. Here, the authors show that nuclear PTEN can interact with the spliceosomal proteins and drive pre-mRNA splicing in a phosphatase-independent manner, in particular, PTEN depletion promotes Golgi extension and secretion through GOLGA2 exon skipping.

Summary: In addition to acting as building blocks for biosynthesis, amino acids might serve as signaling regulators in various physiological and pathological processes. However, it remains unknown whether amino acid levels affect the activities of hematopoietic stem cells (HSCs). By using a genetically encoded fluorescent sensor of the intracellular levels of branched-chain amino acids (BCAAs), we could monitor the dynamics of BCAA metabolism in HSCs. A mitochondrial-targeted 2C-type Ser/Thr protein phosphatase (PPM1K) promotes the catabolism of BCAAs to maintain MEIS1 and p21 levels by decreasing the ubiquitination-mediated degradation controlled by the E3 ubiquitin ligase CDC20. PPM1K deficiency led to a notable decrease in MEIS1/p21 signaling to reduce the glycolysis and quiescence of HSCs, followed by a severe impairment in repopulation activities. Moreover, the deletion of Ppm1k dramatically extended survival in a murine leukemia model. These findings will enhance the current understanding of nutrient signaling in metabolism and function of stem cells. : Liu et al. show that the dynamics of BCAA metabolism in hematopoietic stem cells (HSCs) and leukemia-initiating cells (LICs) can be monitored by a genetically encoded fluorescent sensor. PPM1K promotes BCAA catabolism and maintains the glycolysis and quiescence of HSCs/LICs through the downregulation of CDC20-mediated ubiquitination of MEIS1 and p21. Keywords: branched-chain amino acids, PPM1K, ubiquitination, CDC20, MEIS1/p21, hematopoietic stem cells, leukemia-initiating cells

Summary Phasins are unusual amphiphilic proteins that bind to microbial polyhydroxyalkanoate (PHA) granules in nature and show great potential for various applications in biotechnology and medicine. Despite their remarkable diversity, only the crystal structure of PhaPAh from Aeromonas hydrophila has been solved to date. Based on the structure of PhaPAh, homology models of PhaPAz from Azotobacter sp. FA‐8 and PhaPTD from Halomonas bluephagenesis TD were successfully established, allowing rational mutagenesis to be conducted to enhance the stability and surfactant properties of these proteins. PhaPAz mutants, including PhaPAzQ38L and PhaPAzQ78L, as well as PhaPTD mutants, including PhaPTDQ38M and PhaPTDQ72M, showed better emulsification properties and improved thermostability (6‐10°C higher melting temperatures) compared with their wild‐type homologues under the same conditions. Importantly, the established PhaP homology‐modelling approach, based on the high‐resolution structure of PhaPAh, can be generalized to facilitate the study of other PhaP members.

Polyhydroxyalkanoates (PHA) have been produced by some bacteria as bioplastics for many years. Yet their commercialization is still on the way. A few issues are related to the difficulty of PHA commercialization: namely, high cost and instabilities on molecular weights (Mw) and structures, thus instability on thermo-mechanical properties. The high cost is the result of complicated bioprocessing associated with sterilization, low conversion of carbon substrates to PHA products, and slow growth of microorganisms as well as difficulty of downstream separation. Future engineering on PHA producing microorganisms should be focused on contamination resistant bacteria especially extremophiles, developments of engineering approaches for the extremophiles, increase on carbon substrates to PHA conversion and controlling Mw of PHA. The concept proof studies could still be conducted on E. coli or Pseudomonas spp. that are easily used for molecular manipulations. In this review, we will use E. coli and halophiles as examples to show how to engineer bacteria for enhanced PHA biosynthesis and for increasing PHA competitiveness.

The VHL tumour suppressor gene is lost in approximately 70% of clear cell renal cell carcinoma (ccRCC). In this study, the authors demonstrate that VHL loss in these tumours augments anthracyclines chemotherapy by down-regulation of ALDH2.

Abstract Background Clustered regularly interspaced short palindromic repeats interference (CRISPRi) has provided an efficient approach for targeted gene inhibition. A non-model microorganism Halomonas species TD01 has been developed as a promising industrial producer of polyhydroxyalkanoates (PHA), a family of biodegradable polyesters accumulated by bacteria as a carbon and energy reserve compound. A controllable gene repression system, such as CRISPRi, is needed for Halomonas sp. TD01 to regulate its gene expression levels. Results For the first time CRISPRi was successfully used in Halomonas sp. TD01 to repress expression of ftsZ gene encoding bacterial fission ring formation protein, leading to an elongated cell morphology with typical filamentous shape similar to phenomenon observed with Escherichia coli. CRISPRi was employed to regulate expressions of prpC gene encoding 2-methylcitrate synthase for regulating 3-hydroxyvalerate monomer ratio in PHBV copolymers of 3-hydroxybutyrate (HB) and 3-hydroxyvalerate (HV). Percentages of HV in PHBV copolymers were controllable ranging from less than 1 to 13%. Furthermore, repressions on gltA gene encoding citrate synthase channeled more acetyl-CoA from the tricarboxylic acid (TCA) cycle to poly(3-hydroxybutyrate) (PHB) synthesis. The PHB accumulation by Halomonas sp. TD01 with its gltA gene repressed in various intensities via CRISPRi was increased by approximately 8% compared with the wild type control containing the CRISPRi vector without target. Conclusions It has now been confirmed that the CRISPRi system can be applied to Halomonas sp. TD01, a promising industrial strain for production of various PHA and chemicals under open and continuous fermentation process conditions. In details, the CRISPRi system was successfully designed in this study to target genes of ftsZ, prpC and gltA, achieving longer cell sizes, channeling more substrates to PHBV and PHB synthesis, respectively. CRISPRi can be expected to use for more metabolic engineering applications in non-model organisms.

Microbial polyhydroxyalkanoates (PHA) have been produced as bioplastics for various purposes. Under the support of China National Basic Research 973 Project, we developed synthetic biology methods to diversify the PHA structures into homo-, random, block polymers with improved properties to better meet various application requirements. At the same time, various pathways were assembled to produce various PHA from glucose as a simple carbon source. At the end, Halomonas bacteria were reconstructed to produce PHA in changing morphology for low cost production under unsterile and continuous conditions. The synthetic biology will advance the PHA into a bio- and material industry.

In this study, we aimed to assess the relationship between vitamin D receptor gene polymorphisms and osteoporosis in the Han Chinese population. Articles regarding associations between vitamin D receptor polymorphisms (ApaI rs7975232 and BsmI rs1544410) and osteoporosis were retrieved from databases in November 2014. Eligible studies were tested by the Hardy–Weinberg equilibrium. The odds ratio and 95% confidence interval (95% CI) were analyzed to evaluate the strength of the associations. Pooled effect estimates were derived using a fixed-effect model and a random-effect model according to the heterogeneity of the test results. A subgroup analysis by study type and a sensitivity analysis based on studies that conform to the Hardy–Weinberg equilibrium and studies with postmenopausal women as participants were performed. This meta-analysis involved 15 eligible studies including 1580 cases and 1389 controls. The pooled estimated odds ratios in the dominant and additive genetic models were 0.73 (95% CI: 0.46–1.14, p=0.17) and 1.01 (95% CI: 0.77–1.33, p=0.81), respectively, for rs7975232 and 1.01 (95% CI: 0.81–1.26, p=0.91) and 1.01 (95% CI: 0.77–1.33, p=0.92), respectively, for rs1544410. The subgroup analysis showed that regardless of the dominant or additive genetic model, the effect of pooled odds ratios for rs7975232 and rs1544410 was insignificant. The sensitivity analysis also showed that the pooled effect was not significantly changed. In conclusion, no evidence of association is apparent between polymorphisms of vitamin D receptor genes and osteoporosis risk in the Han Chinese population.

Abstract Background CD274 (programmed death ligand 1, also known as B7H1) is expressed in both solid tumors and hematologic malignancies and is of critical importance for the escape of tumor cells from immune surveillance by inhibiting T cell function via its receptor, programmed death 1 (PD-1). Increasing evidence indicates that functional monoclonal antibodies of CD274 may potently enhance the antitumor effect in many cancers. However, the role of CD274 in leukemia-initiating cells (LICs) remains largely unknown. Methods We established an MLL-AF9-induced acute myeloid leukemia (AML) model with wild-type (WT) and CD274-null mice to elucidate the role of CD274 in the cell fates of LICs, including self-renewal, differentiation, cell cycle, and apoptosis. RNA sequencing was performed to reveal the potential downstream targets, the results of which were further validated both in vitro and in vivo. Results In silico analysis indicated that CD274 level was inversely correlated with the overall survival of AML patients. In Mac-1+/c-Kit+ mouse LICs, CD274 was expressed at a much higher level than in the normal hematopoietic stem cells (HSCs). The survival of the mice with CD274-null leukemia cells was dramatically extended during the serial transplantation compared with that of their WT counterparts. CD274 deletion led to a significant decrease in LIC frequency and arrest in the G1 phase of the cell cycle. Interestingly, CD274 is not required for the maintenance of HSC pool as shown in our previous study. Mechanistically, we demonstrated that the levels of both phospho-JNK and Cyclin D2 were strikingly downregulated in CD274-null LICs. The overexpression of Cyclin D2 fully rescued the loss of function of CD274. Moreover, CD274 was directly associated with JNK and enhanced the downstream signaling to increase the Cyclin D2 level, promoting leukemia development. Conclusions The surface immune molecule CD274 plays a critical role in the proliferation of LICs. The CD274/JNK/Cyclin D2 pathway promotes the cell cycle entry of LICs, which may serve as a novel therapeutic target for the treatment of leukemia.

Fatty acid oxidation dependency of leukemia cells has been documented in recent studies. Pharmacologic inhibition of fatty acid oxidation, thereby, displays significant effects in suppressing leukemia. 2-Bromopalmitate, a palmitate analogue, was initially identified as an inhibitor of fatty acid oxidation, and recently recognized as an inhibitor of protein palmitoylation. However, the effects of 2-Bromopalmitate on leukemia and its cellular targets remain obscure. Herein, we discover in cultured cell lines, a transplantable mouse model, and primary blasts that 2-Bromopalmitate presents synergistic differentiation induction with all-trans retinoic acid in acute promyelocytic leukemia. Moreover, 2-Bromopalmitate overcomes all-trans retinoic acid resistance in all-trans retinoic acid-resistant cells and leukemic mice. Mechanistically, 2-Bromopalmitate covalently binds at cysteine 105 and cysteine 174 of retinoic acid receptor alpha (RARα) and stabilizes RARα protein in the presence of all-trans retinoic acid which is known to induce RARα degradation, leading to enhanced transcription of RARα-target genes. Mutation of both cysteines largely abrogates the synergistic effect of 2-Bromopalmitate on all-trans retinoic acid-induced differentiation, demonstrating that 2-Bromopalmitate promotes all-trans retinoic acid-induced differentiation through binding RARα. All-trans retinoic acid-based regimens including arsenic trioxide or chemotherapy, as preferred therapy for acute promyelocytic leukemia, induce adverse events and irreversible resistance. We expect that combining all-trans retinoic acid with 2-Bromopalmitate would be a promising therapeutic strategy for acute promyelocytic leukemia, especially for overcoming all-trans retinoic acid resistance of relapsed acute promyelocytic leukemia patients.

Various methods for editing specific sites in the Escherichia coli chromosome are available, and gene-size (∼1 kb) integration into a single site or to introduce deletions, short insertions or point mutations into multiple sites can be conducted in a short period of time. However, a method for rapidly integrating multiple gene-size sequences into different sites has not been developed yet. Here, we describe a method and plasmid system that makes it possible to simultaneously insert genes into multiple specific loci of the E. coli genome without the need for chromosomal markers. The method uses a CRISPR-Cas12a system to eliminate unmodified cells by double-stranded DNA cleavage in conjunction with the phage-derived λ-Red recombinases to facilitate recombination between the chromosome and the donor DNA. We achieved the insertion of up to 3 heterologous genes in one round of recombination and selection. To demonstrate the practical application of this gene-insertion method, we constructed a recombinant E. coli producing an industrially useful chemical, 5-aminolevulinic acid (ALA), with high-yield. Moreover, a similar two-plasmid system was built to edit the genome of the extremophile Halomonas bluephagenesis.

Targeting leukemia initiating cells is considered to be an effective way to cure leukemia, for which it is critical to identify novel therapeutic targets. Herein, we demonstrate that CD244, which was initially reported as a key regulator for natural killer cells, is highly expressed on both mouse and human leukemia initiating cells. Upon CD244 knockdown, human leukemia cell lines and primary leukemia cells have markedly impaired proliferation abilities both in vitro and in vivo. Interestingly, the repopulation ability of both mouse and human hematopoietic stem cells is not impaired upon CD244 knockdown. Using an MLL-AF9-induced murine acute myeloid leukemia model, we show that leukemogenesis is dramatically delayed upon CD244 deletion, together with remarkably reduced Mac1+/c-Kit+ leukemia cells (enriched for leukemia initiating cells). Mechanistically, we reveal that CD244 is associated with c-Kit and p27 except for SHP-2 as previously reported. CD244 co-operates with c-Kit to activate SHP-2 signaling to dephosphorylate p27 and maintain its stability to promote leukemia development. Collectively, we provide intriguing evidence that the surface immune molecule CD244 plays an important role in the maintenance of stemness of leukemia initiating cells, but not in hematopoietic stem cells. CD244 may represent a novel therapeutic target for the treatment of acute myeloid leukemia.

Natural rubber is a kind of indispensable biopolymers with great use and strategic importance in human society. However, its production relies almost exclusively on rubber-producing plants Hevea brasiliensis, which have high requirements for growth conditions, and the mechanism of natural rubber biosynthesis remains largely unknown. In the past two decades, details of the rubber chain polymerization and proteins involved in natural rubber biosynthesis have been investigated intensively. Meanwhile, omics and other advanced biotechnologies bring new insight into rubber production and development of new rubber-producing plants. This review summarizes the achievements of the past two decades in understanding the biosynthesis of natural rubber, especially the massive information obtained from the omics analyses. Possibilities of natural rubber biosynthesis in vitro or in genetically engineered microorganisms are also discussed.

China accounts for almost half of the total number of liver cancer cases and deaths worldwide, and hepatocellular carcinoma (HCC) is the most primary liver cancer. Snail family transcriptional repressor 2 (SNAI2) is known as an epithelial to mesenchymal transition-inducing transcription factor that drives neoplastic epithelial cells into mesenchymal phenotype. However, the roles of endogenous SNAI2 remain controversial in different types of malignant tumors. Herein, we surprisingly identify that anchorage-independent growth, including the formation of tumor sphere and soft agar colony, is significantly increased when SNAI2 expression is inhibited by shRNAs in HCC cells. Suppression of SNAI2 suffices to up-regulate several cancer stem genes. Although unrelated to the metastatic ability, SNAI2 inhibition does increase the efflux of Hoechst 33342 and enhance multidrug resistance in vitro and in vivo. In agreement with this data, we demonstrate for the first time that decreasing SNAI2 level can transcriptionally upregulate several ATP binding cassette (ABC) transporter genes such as ABCB1. Moreover, ABC transporters' inhibitor verapamil can rescue the multidrug resistance induced by SNAI2 inhibition. Our results implicate that SNAI2 behaves as a tumor suppressor by inhibiting multidrug resistance via suppressing ABC transporter genes in HCC cells.

p16INK4A (p16) binds to cyclin-dependent kinase 4/6, negatively regulates cell growth. Recent studies have led to an understanding of additional biologic functions for p16; however, the detailed mechanisms involved are still elusive. In this article, we show an unexpected expression of anion exchanger 1 (AEi) in the cytoplasm in poorly, moderately differentiated gastric, colonic adenocarcinoma cells, in its interaction with p16, thereby sequestrating the protein in the cytoplasm. Genetic alterations of p16, AEi were not detectable. Forced expression of AEi in these cells sequestrated more p16 in the cytoplasm, whereas small interfering RNA-mediated silencing of AEi in the cells induced the release of p16 from the cytoplasm to the nucleus, leading to cell death, growth inhibition of tumor cells. By analyzing tissue samples obtained from patients with gastric, colonic cancers, we found that 83.33% of gastric cancers, 56.52% of colonic cancers coexpressed AEi, p16 in the cytoplasm. We conclude that AEi plays a crucial role in the pathogenesis of gastric, colonic adenocarcinoma, that p16 dysfunction is a novel pathway of carcinogenesis.

Previously we reported that the expression of promyelocytic leukemia (PML)-retinoic acid receptor alpha (RARα) fusion gene, which is caused by specific translocation (15;17) in acute promyelocytic leukemia, can enhance constitutive autophagic activity in leukemic and nonleukemic cells, and PML overexpression can sequestrate part of microtubule-associated protein light chain 3 (LC3) protein in PML nuclear bodies, suggesting that LC3 protein also distributes into nuclei although it is currently thought to function primarily in the cytoplasm, the site of autophagosomal formation. However, its potential significance of nucleoplasmic localizations remains greatly elusive. Here we demonstrate that PML interacts with LC3 in a cell type-independent manner as assessed by Co-IP assay and co-localization observation. Overexpressed PML significantly coprecipitates with endogenous and nuclear LC3 protein. Furthermore, a fraction of endogenous PML protein is found to be co-localized with LC3 protein under steady state condition, which is further enhanced by IFNα induction, indicating that PML up-regulation potentiates this interaction. Additionally, DsRed-PML associates with EGFP-LC3 during telophase and G1 phase but not in metaphase and anaphase. Two potential LC3-interacting region (LIR) motifs in PML are required for interaction of PML with LC3 while this association is independent of autophagic activity. Finally, we show that interaction between PML and LC3 contributes to cell growth inhibition function of PML. Considering that PML is an important tumor suppressor, we propose that nuclear portion of LC3 protein may associate with PML to control cell growth for prevention and inhibition of cancer occurrence and development.