Metformin synergizes with PD-1 blockade to promote normalization of tumor vessels via CD8T cells and IFNγ.

Tumor blood vessels are highly leaky in structure and have poor blood perfusion, which hampers infiltration and function of CD8T cells within tumor. Normalizing tumor vessels is thus thought to be important in promoting the flux of immune T cells and enhancing ant-tumor immunity. However, how tumor vasculature is normalized is poorly understood. Metformin (Met) combined with ant-PD-1 therapy is known to stimulate proliferation of and to produce large amounts of IFNγ from tumor-infiltrating CD8T lymphocytes (CD8TILs). We found that the combination therapy promotes the pericyte coverage of tumor vascular endothelial cells (ECs) to improve blood perfusion and that it suppresses the hyperpermeability through the increase of VE-cadherin. Peripheral node addressin(PNAd) and vascular cell adhesion molecule (VCAM)-1, both implicated to promote tumor infiltration of CD8T cells, were also increased. Importantly, tumor vessel normalization, characterized as the reduced 70-kDa dextran leakage and the enhancement of VE-cadherin and VCAM-1, were canceled by anti-CD8 Ab or anti-IFNγ Ab injection to mice. The increased CD8TILs were also abrogated by anti-IFNγ Ab injection. In vascular ECs, flow cytometry analysis revealed that pSTAT1 expression was found to be associated with VE-cadherin expression. Moreover, in vitro treatment with Met and IFNγ enhanced VE-cadherin and VCAM-1 on human umbilical vein endothelial cells (HUVECs). The Kaplan-Meier method revealed a correlation of VE-cadherin or VCAM-1 levels with overall survival in patients treated with immune checkpoint inhibitors. These data indicate that IFNγ-mediated cross talk of CD8TILs with tumor vessels is important for creating a better tumor microenvironment and maintaining sustained antitumor immunity.

Electron bifurcation and fluoride efflux systems implicated in defluorination of perfluorinated unsaturated carboxylic acids by Acetobacterium spp.

Enzymatic cleavage of C─F bonds in per- and polyfluoroalkyl substances (PFAS) is largely unknown but avidly sought to promote systems biology for PFAS bioremediation. Here, we report the reductive defluorination of α, ß-unsaturated per- and polyfluorocarboxylic acids by Acetobacterium spp. The microbial defluorination products were structurally confirmed and showed regiospecificity and stereospecificity, consistent with their formation by enzymatic reactions. A comparison of defluorination activities among several Acetobacterium species indicated that a functional fluoride exporter was required for the detoxification of the released fluoride. Results from both in vivo inhibition tests and in silico enzyme modeling suggested the involvement of enzymes of the flavin-based electron-bifurcating caffeate reduction pathway [caffeoyl-CoA reductase (CarABCDE)] in the reductive defluorination. This is a report on specific microorganisms carrying out enzymatic reductive defluorination of PFAS, which could be linked to electron-bifurcating reductases that are environmentally widespread.

Tolerance threshold of a pelagic species in China to total dissolved gas supersaturation: from the perspective of survival characteristics and swimming ability.

Total dissolved gas (TDG) supersaturation downstream of dams can occur in the Yangtze River basin and is known to cause stress and even death in fish. Consequently, it is important to establish tolerance thresholds of endemic fish to protect local aquatic resources. We conducted experiments to assess survival characteristics and swimming ability of bighead carp, an important commercial fish dwelling in the Yangtze River, to evaluate its tolerance threshold to TDG supersaturation. The typical external symptoms of gas bubble trauma (GBT) were observed and the time when the fish lost equilibrium and died were recorded. The results showed that the mortality occurred when TDG level exceeded 125%, with obvious symptoms such as exophthalmos and bubbles on the head. The interval between loss of equilibrium and mortality decreased with an increase in TDG level. Neither exposure time nor TDG level significantly affected the critical swimming speed (Ucrit) of fish exposed to non-lethal exposure (110%, 120% and 125% TDG) over a 7 day period. Significant reductions in Ucrit were found under 130% and 135% TDG conditions when the exposure lasted 52.0 h and 42.9 h, respectively. The Ucrit also significantly decreased after exposure of 1.6 h under 140% TDG condition. Moreover, after exposure to 140% TDG for 39.2 h, 135% TDG for 56.5 h and 130% TDG for 95.9 h, bighead carp were transferred into air saturated water to recover for 24 h or 48 h; however, swimming performance remained impaired. The results of this study indicate that 125% TDG was the highest TDG level where limited mortality was observed and the swimming ability was not impaired, showing that 125% TDG can be set as the tolerance threshold of this species to guide the operation of dams in the Yangtze River Basin.

Phycocyanin from microalgae: A comprehensive review covering microalgal culture, phycocyanin sources and stability.

As food safety continues to gain prominence, phycocyanin (PC) is increasingly favored by consumers as a natural blue pigment, which is extracted from microalgae and serves the dual function of promoting health and providing coloration. Spirulina-derived PC demonstrates exceptional stability within temperature ranges below 45 °C and under pH conditions between 5.5 and 6.0. However, its application is limited in scenarios involving high-temperature processing due to its sensitivity to heat and light. This comprehensive review provides insights into the efficient production of PC from microalgae, covers the metabolic engineering of microalgae to increase PC yields and discusses various strategies for enhancing its stability in food applications. In addition to the most widely used Spirulina, some red algae and Thermosynechococcus can serve as good source of PC. The genetic and metabolic manipulation of microalgae strains has shown promise in increasing PC yield and improving its quality. Delivery systems including nanoparticles, hydrogels, emulsions, and microcapsules offer a promising solution to protect and extend the shelf life of PC in food products, ensuring its vibrant color and health-promoting properties are preserved. This review highlights the importance of metabolic engineering, multi-omics applications, and innovative delivery systems in unlocking the full potential of this natural blue pigment in the realm of food applications, provides a complete overview of the entire process from production to commercialization of PC, including the extraction and purification.

Aerobic Biotransformation and Defluorination of Fluoroalkylether Substances (ether PFAS): Substrate Specificity, Pathways, and Applications.

Fluoroalkylether substances (ether PFAS) constitute a large group of emerging PFAS with uncertain environmental fate. Among them, GenX is the well-known alternative to perfluorooctanoic acid and one of the six proposed PFAS to be regulated by the U.S. Environmental Protection Agency. This study investigated the structure-biodegradability relationship for 12 different ether PFAS with a carboxylic acid headgroup in activated sludge communities. Only polyfluorinated ethers with at least one -CH2- moiety adjacent to or a C=C bond in the proximity of the ether bond underwent active biotransformation via oxidative and hydrolytic O-dealkylation. The bioreactions at ether bonds led to the formation of unstable fluoroalcohol intermediates subject to spontaneous defluorination. We further demonstrated that this aerobic biotransformation/defluorination could complement the advanced reduction process in a treatment train system to achieve more cost-effective treatment for GenX and other recalcitrant perfluorinated ether PFAS. These findings provide essential insights into the environmental fate of ether PFAS, the design of biodegradable alternative PFAS, and the development of cost-effective ether PFAS treatment strategies.

Definition of fatty acid transport protein-2 (FATP2) structure facilitates identification of small molecule inhibitors for the treatment of diabetic complications.

Diabetes is a major public health problem due to morbidity and mortality associated with end organ complications. Uptake of fatty acids by Fatty Acid Transport Protein-2 (FATP2) contributes to hyperglycemia, diabetic kidney and liver disease pathogenesis. Because FATP2 structure is unknown, a homology model was constructed, validated by AlphaFold2 prediction and site-directed mutagenesis, and then used to conduct a virtual drug discovery screen. In silico similarity searches to two low-micromolar IC50 FATP2 inhibitors, followed by docking and pharmacokinetics predictions, narrowed a diverse 800,000 compound library to 23 hits. These candidates were further evaluated for inhibition of FATP2-dependent fatty acid uptake and apoptosis in cells. Two compounds demonstrated nanomolar IC50, and were further characterized by molecular dynamic simulations. The results highlight the feasibility of combining a homology model with in silico and in vitro screening, to economically identify high affinity inhibitors of FATP2, as potential treatment for diabetes and its complications.

Tracking Chinese newspaper coverage of elephant ivory through topic modeling.

Mass media worldwide has contributed to increasing awareness of the illegal wildlife trade and its significant impact on wildlife conservation. We used mass media coverage as a proxy for macro-level public opinion to analyze the media framing of elephant ivory in 6394 Chinese newspaper articles published from 2000 to 2021 and thus determine the effects of wildlife policies on public opinion. We focused on 2 events: the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) approval of China as a trading partner in the purchase and import of ivory stockpiles from Africa in July 2008 and the Chinese government's announcement of a domestic ivory ban in December 2016. Using latent Dirichlet allocation topic modeling, we identified 8 topics about elephant ivory and grouped them into 3 frames: ivory arts and culture, ivory crimes, and elephant conservation. Over the last 2 decades, topics related to ivory crimes remained the most prevalent in news articles. Topics about ivory arts and culture showed a significant shift in media salience before and after the 2 events (from 0.44 to 0.19 and from 0.08 to 0.15, respectively, p < 0.05), whereas the other 2 frames did not change significantly. Contrary to popular belief, our results indicated that Chinese macro-level public opinion on ivory had become more negative following the CITES approval of ivory importation and less negative after the ivory ban announcement, at least for certain periods. The relationship between mass media, public opinion, and wildlife trade policies is complex and requires further examination of the sociopolitical dynamics that influence media narratives. Our results showed the value of topic modeling in monitoring and assessing media representations of wildlife issues in the era of big data. Conservationists should remain vigilant of mass media coverage and collaborate with media practitioners to produce comprehensive narratives on wildlife issues if resources permit.

Los medios masivos han contribuido a una mayor conciencia mundial del mercado ilegal de fauna y el impacto significativo que tiene sobre la conservación. Usamos la cobertura de los medios masivos como sustituto de la opinión pública a nivel macro para analizar el encuadre mediático que le dan al marfil 6,394 artículos publicados en periódicos chinos entre el 2000 y 2021 para así determinar los efectos que tienen las políticas de fauna sobre la opinión pública. Nos enfocamos en dos eventos: la autorización que dio la Convención sobre el Comercio Internacional de Especies Amenazadas (CITES) a China como socio comercial en la compra e importación de reservas de marfil desde África en julio de 2008 y la prohibición doméstica de marfil anunciada por el gobierno chino en diciembre de 2016. Usamos el modelado de asignación latente de Dirichlet para identificar ocho temas sobre el marfil y los agrupamos en tres encuadres: arte y cultura del marfil, crimen del marfil y conservación de elefantes. Durante las últimas dos décadas, los temas relacionados con los crímenes del marfil fueron los más prevalentes en los artículos periodísticos. Los temas relacionados al arte y cultura del marfil mostraron un cambio significativo en la relevancia mediática antes y después de los dos eventos (de 0.44 a 0.19 y de 0.08 a 0.15, respectivamente, p<0.05), mientras que los otros dos encuadres no cambiaron significativamente. Contrario a las creencias populares, nuestros resultados indicaron que la opinión pública a nivel macro sobre el marfil en China se ha vuelto más negativa después de la autorización de CITES y menos negativa después de la prohibición del marfil, al menos durante ciertos periodos. La relación entre los medios masivos, la opinión pública y las políticas del comercio de fauna es compleja y requiere un análisis más profundo de las dinámicas sociopolíticas que influyen sobre las narrativas mediáticas. Nuestros resultados muestran el valor del modelado de temas en el monitoreo y evaluación de la representación en medios de los temas sobre fauna en tiempos de los macrodatos. Los conservacionistas deberían permanecer atentos a la cobertura de los medios masivos y colaborar con los profesionales de los medios para producir narraciones completas sobre la fauna si los recursos lo permiten.

Fucoxanthin from marine microalgae: A promising bioactive compound for industrial production and food application.

Fucoxanthin attracts increasing attentions due to its potential health benefits, which has been exploited in several food commodities. However, fucoxanthin available for industrial application is mainly derived from macroalgae, and is not yet sufficiently cost-effective compared with microalgae. This review focuses on the strategies to improve fucoxanthin productivity and approaches to reduce downstream costs in microalgal production. Here we comprehensively and critically discuss ways and methods to increase the cell growth rate and fucoxanthin content of marine microalgae, including strain screening, condition optimization, design of culture mode, metabolic and genetic engineering, and scale-up production of fucoxanthin. The approaches in downstream processes provide promising alternatives for fucoxanthin production from marine microalgae. Besides, this review summarizes fucoxanthin improvements in solubility and bioavailability by delivery system of emulsion, nanoparticle, and hydrogel, and discusses fucoxanthin metabolism with gut microbes. Fucoxanthin production from marine microalgae possesses numerous advantages in environmental sustainability and final profits to meet incremental global market demands of fucoxanthin. Strategies of adaptive evolution, multi-stage cultivation, and bioreactor improvements have tremendous potentials to improve economic viability of the production. Moreover, fucoxanthin is promising as the microbiota-targeted ingredient, and nanoparticles can protect fucoxanthin from external environmental factors for improving the solubility and bioavailability.

A review of compaction effect on subsurface processes in soil: Implications on stormwater treatment in roadside compacted soil.

Sustainable cities require spacious infrastructures such as roadways to serve multiple functions, including transportation and water treatment. This can be achieved by installing stormwater control measures (SCM) such as biofilters and swales on the roadside compacted soil, but compacted soil limits infiltration and other functions of SCM. Understanding the effect of compaction on subsurface processes could help design SCM that could alleviate the negative impacts of compaction. Therefore, we synthesize reported data on compaction effects on subsurface processes, including infiltration rate, plant health, root microbiome, and biochemical processes. The results show that compaction could reduce runoff infiltration rate, but adding sand to roadside soil could alleviate the negative impact of compaction. Compaction could decrease the oxygen diffusion rate in the root zone, thereby affecting plant root activities, vegetation establishment, and microbial functions in SCM. The impacts of compaction on carbon mineralization rate and root biomass vary widely based on soil type, aeration status, plant species, and inherent soil compaction level. As these processes are critical in maintaining the long-term functions of SCM, the analysis would help develop strategies to alleviate the negative impacts of compaction and turn road infrastructure into a water solution in sustainable cities.

Electron-bifurcation and fluoride efflux systems in Acetobacterium spp. drive defluorination of perfluorinated unsaturated carboxylic acids.

Enzymatic cleavage of C-F bonds in per- and polyfluoroalkyl substances (PFAS) is largely unknown but avidly sought to promote systems biology for PFAS bioremediation. Here, we report the reductive defluorination of α, ß-unsaturated per- and polyfluorocarboxylic acids by Acetobacterium spp. Two critical molecular features in Acetobacterium species enabling reductive defluorination are (i) a functional fluoride efflux transporter (CrcB) and (ii) an electron-bifurcating caffeate reduction pathway (CarABCDE). The fluoride transporter was required for detoxification of released fluoride. Car enzymes were implicated in defluorination by the following evidence: (i) only Acetobacterium spp. with car genes catalyzed defluorination; (ii) caffeate and PFAS competed in vivo ; (iii) models from the X-ray structure of the electron-bifurcating reductase (CarC) positioned the PFAS substrate optimally for reductive defluorination; (iv) products identified by 19 F-NMR and high-resolution mass spectrometry were consistent with the model. Defluorination biomarkers identified here were found in wastewater treatment plant metagenomes on six continents.

Ferulic Acid Mediates Metabolic Syndrome via the Regulation of Hepatic Glucose and Lipid Metabolisms and the Insulin/IGF-1 Receptor/PI3K/AKT Pathway in Palmitate-Treated HepG2 Cells.

Ferulic acid (FA) is one of the most abundant bound phenolics in whole grains, partly contributing to its preventive effects on metabolic syndrome (MetS). The study aims to investigate if FA mediates MetS through the regulation of hepatic metabolisms and the insulin receptor related pathways in the palmitate-treated HepG2 cells (MetS model). We found that FA (50, 100, and 200 µM) dramatically ameliorated the lipid accumulation in the MetS model. FA significantly decreased the activities of the gluconeogenic enzymes, G6Pase and PEPCK, downregulated the lipogenic enzyme FAS-1, and upregulated the lipolytic enzyme CPT-1 by regulating a series of transcriptional factors including HNF4α, FOXO-1, SREBP-1c, and PPAR-γ. Notably, we found that FA's ability to alleviate MetS is achieved by activating the insulin receptor/PI3K/AKT pathway. Our results validated the effects of FA on mediating the metabolic disorders of lipid and glucose pathways and unveiled its potential intracellular mechanisms for the prevention of MetS.

Nutrient Condition in the Microenvironment Determines Essential Metabolisms of CD8+ T Cells for Enhanced IFNγ Production by Metformin.

Metformin (Met), a first-line drug for type 2 diabetes, lowers blood glucose levels by suppressing gluconeogenesis in the liver, presumably through the liver kinase B1-dependent activation of AMP-activated protein kinase (AMPK) after inhibiting respiratory chain complex I. Met is also implicated as a drug to be repurposed for cancers; its mechanism is believed identical to that of gluconeogenesis inhibition. However, AMPK activation requires high Met concentrations at more than 1 mM, which are unachievable in vivo. The immune-mediated antitumor response might be the case in a low dose Met. Thus, we proposed activating or expanding tumor-infiltrating CD8+ T cells (CD8TILs) in a mouse model by orally administering Met in free drinking water. Here we showed that Met, at around 10 µM and a physiologically relevant concentration, enhanced production of IFNγ,TNFα and expression of CD25 of CD8+ T cells upon TCR stimulation. Under a glucose-rich condition, glycolysis was exclusively involved in enhancing IFNγ production. Under a low-glucose condition, fatty acid oxidation or autophagy-dependent glutaminolysis, or both, was also involved. Moreover, phosphoenolpyruvate carboxykinase 1 (PCK1), converting oxaloacetate to phosphoenolpyruvate, became essential. Importantly, the enhanced IFNγ production was blocked by a mitochondrial ROS scavenger and not by an inhibitor of AMPK. In addition, IFNγ production by CD8TILs relied on pyruvate translocation to the mitochondria and PCK1. Our results revealed a direct effect of Met on IFNγ production of CD8+ T cells that was dependent on differential metabolic pathways and determined by nutrient conditions in the microenvironment.

NMR resonance assignments of the DNA binding domain of mouse Junctophilin-2.

Junctophilin-2 (JP2) is a critical structural protein in the heart by stabilizing junctional membrane complexes between the plasma membrane and sarcoplasmic reticula responsible for precise Ca2+ regulation. Such complexes are essential for efficient cardiomyocyte contraction and adaptation to altered cardiac workload conditions. Mutations in the JPH2 gene that encodes JP2 are associated with inherited cardiomyopathies and arrhythmias, and disruption of JP2 function is lethal. Interestingly, cardiac stress promotes the proteolytic cleavage of JP2 that triggers the translocation of its N-terminal fragment into the nucleus to repress maladaptive gene transcription. We previously found that the central region of JP2 is responsible for mediating direct DNA binding interactions. Recent structural studies indicate that this region serves as a structural role in the cytosolic form of JP2 by folding into a single continuous α-helix. However, the structural basis of how this DNA-binding domain interacts with DNA is not known. Here, we report the backbone and sidechain assignments of the DNA-binding domain (residues 331-413) of mouse JP2. These assignments reveal that the JP2 DNA binding domain is an intrinsically disordered protein and contains two α-helices located in the C-terminal portion of the protein. Moreover, this protein binds to DNA in a similar manner to that shown previously by electrophoretic mobility shift assays. Therefore, these assignments provide a framework for further structural studies into the interaction of this JP2 domain with DNA for the elucidation of transcriptional regulation of stress-responsive genes as well as its role in the stabilization of junctional membrane complexes.

Gene Therapy With the N-Terminus of Junctophilin-2 Improves Heart Failure in Mice.

BACKGROUND: Transcriptional remodeling is known to contribute to heart failure (HF). Targeting stress-dependent gene expression mechanisms may represent a clinically relevant gene therapy option. We recently uncovered a salutary mechanism in the heart whereby JP2 (junctophilin-2), an essential component of the excitation-contraction coupling apparatus, is site-specifically cleaved and releases an N-terminal fragment (JP2NT [N-terminal fragment of JP2]) that translocates into the nucleus and functions as a transcriptional repressor of HF-related genes. This study aims to determine whether JP2NT can be leveraged by gene therapy techniques for attenuating HF progression in a preclinical pressure overload model. METHODS: We intraventricularly injected adeno-associated virus (AAV) (2/9) vectors expressing eGFP (enhanced green fluorescent protein), JP2NT, or DNA-binding deficient JP2NT (JP2NTΔbNLS/ARR) into neonatal mice and induced cardiac stress by transaortic constriction (TAC) 9 weeks later. We also treated mice with established moderate HF from TAC stress with either AAV-JP2NT or AAV-eGFP. RNA-sequencing analysis was used to reveal changes in hypertrophic and HF-related gene transcription by JP2NT gene therapy after TAC. Echocardiography, confocal imaging, and histology were performed to evaluate heart function and pathological myocardial remodeling following stress. RESULTS: Mice preinjected with AAV-JP2NT exhibited ameliorated cardiac remodeling following TAC. The JP2NT DNA-binding domain is required for cardioprotection as its deletion within the AAV-JP2NT vector prevented improvement in TAC-induced cardiac dysfunction. Functional and histological data suggest that JP2NT gene therapy after the onset of cardiac dysfunction is effective at slowing the progression of HF. RNA-sequencing analysis further revealed a broad reversal of hypertrophic and HF-related gene transcription by JP2NT overexpression after TAC. CONCLUSIONS: Our prevention- and intervention-based approaches here demonstrated that AAV-mediated delivery of JP2NT into the myocardium can attenuate stress-induced transcriptional remodeling and the development of HF when administered either before or after cardiac stress initiation. Our data indicate that JP2NT gene therapy holds great potential as a novel therapeutic for treating hypertrophy and HF.

Estimation of CO2 emission in reservoir coupling floating chamber and thin boundary layer methods.

With the growing development of hydropower projects all over the world, the excessive greenhouse gas (GHG) emissions from increasing reservoirs have drawn public concern. While precise evaluations of GHG emissions are urgently needed, the widely applied methods including floating chamber (FC) method and thin boundary layer (TBL) method are unsatisfactory. In this paper, a new methodology of estimating CO2 emission coupling FC and TBL methods was proposed. Three efforts were achieved stepwise:1) the CO2 transfer coefficient was determined combining the measurements of FC method and TBL model; 2) a semi-empirical model connecting gas-water transfer coefficient and near-surface water turbulence in reservoir was proposed; 3) finally, since surface turbulence in the reservoir could be describe in detail by numerical simulation, integration thousands of discrete cells of local fluxes could be applied to estimate the total CO2 emission with an improved precision. Nine locations in Xiangjiaba Reservoir were selected as a demo study for applying the method, the CO2 emission in the whole reservoir was about 1.37 kg/s. With a deeper insight into the law of gas transfer and an elaborate consideration of the whole reservoir, this study is expected to provide a new approach and technical support to estimate the CO2 emissions accurately in reservoirs.

Systematic metabolic tools reveal underlying mechanism of product biosynthesis in Chromochloris zofingiensis.

This study comprehensively explored underlying mechanism of fed-batch culture on product biosynthesis in Chromochloris zofingiensis by dynamic model, targeted metabolite determination, enzyme activity analysis, and 13C tracer-based metabolic flux analysis. Based on dynamic models of cell growth and product formation, exponential fed-batch culture and fed-batch culture based on pH changes were established to increase biomass concentration by 20.05-fold and 18.28-fold, respectively. Exponential fed-batch culture exhibited great potentials in biodiesel and protein productions from microalgae. Systematic metabolic tools revealed fed-batch culture limited photosynthetic efficiency by inhibiting photosystem and Rubisco activity, while strengthened respiratory action to provide more substances and energy for product biosynthesis. Fed-batch culture elevated biosynthetic capability for carotenoid and lipid by promoting related metabolic flux and contents of pyruvate and ace-CoA. Finally, economic analysis revealed biomass cost was decreased to 1.99 $/kg from 2.39 $/kg, suggesting fed-batch culture was a cost-effective strategy to improve economic viability of microalgal production.

High-fiber diet mitigates maternal obesity-induced cognitive and social dysfunction in the offspring via gut-brain axis.

Maternal obesity has been reported to be related to neurodevelopmental disorders in the offspring. However, the underlying mechanisms and effective interventions remain unclear. This cross-sectional study with 778 children aged 7-14 years in China indicated that maternal obesity is strongly associated with children's lower cognition and sociality. Moreover, it has been demonstrated that maternal obesity in mice disrupted the behavior and gut microbiome in offspring, both of which were restored by a high-fiber diet in either dams or offspring via alleviating synaptic impairments and microglial maturation defects. Co-housing and feces microbiota transplantation experiments revealed a causal relationship between microbiota and behavioral changes. Moreover, treatment with the microbiota-derived short-chain fatty acids also alleviated the behavioral deficits in the offspring of obese dams. Together, our study indicated that the microbiota-metabolites-brain axis may underlie maternal obesity-induced cognitive and social dysfunctions and that high dietary fiber intake could be a promising intervention.

Methionine restriction alleviates high-fat diet-induced obesity: Involvement of diurnal metabolism of lipids and bile acids.

Circadian misalignment induced by a high-fat diet (HFD) increases the risk of metabolic diseases. Methionine restriction (MR) is known to have the potential of alleviating obesity by improving insulin sensitivity. However, the role of the circadian clock in mediating the effects of MR on obesity-related metabolic disorders remains unclear. Ten-week-old male C57BL/6 J mice were fed with a low-fat diet (LFD) or a HFD for 4 wk., followed with a full diet (0.86% methionine, w/w) or a methionine-restricted diet (0.17% methionine, w/w) for 8 wk. Our results showed that MR attenuated insulin resistance triggered by HFD, especially at ZT12. Moreover, MR led to a time-specific enhancement of the expression of FGF21 and activated the AMPK/PGC-1α signaling. Notably, MR upregulated the cyclical levels of cholic acid (CA) and chenodeoxycholic acid (CDCA), and downregulated the cyclical level of deoxycholic acid (DCA) in the dark phase. MR restored the HFD-disrupted cyclical fluctuations of lipidolysis genes and BAs synthetic genes and improved the circulating lipid profile. Also, MR improved the expressions of clock-controlled genes (CCGs) in the liver and the brown adipose tissue throughout one day. In conclusion, MR exhibited the lipid-lowering effects on HFD-induced obesity and restored the diurnal metabolism of lipids and BAs, which could be partly explained by improving the expression of CCGs. These findings suggested that MR could be a potential nutritional intervention for attenuating obesity-induced metabolic misalignment.

Alternate-day fasting alleviates diabetes-induced glycolipid metabolism disorders: roles of FGF21 and bile acids.

Glycolipid metabolism disorder is one of the causes of type 2 diabetes (T2D). Alternate-day fasting (ADF) is an effective dietary intervention to counteract T2D. The present study is aimed to determine the underlying mechanisms of the benefits of ADF metabolic on diabetes-induced glycolipid metabolism disorders in db/db mice. Here, leptin receptor knock-out diabetic mice were subjected to 28 days of isocaloric ADF. We found that ADF prevented insulin resistance and bodyweight gain in diabetic mice. ADF promoted glycogen synthesis in both liver and muscle. ADF also activated recombinant insulin receptor substrate-1 (IRS-1)/protein kinase B (AKT/PKB) signaling，inactivated inflammation related AMP-activated protein kinase (AMPK) and the inflammation-regulating nuclear factor kappa-B (NF-κB) signaling in the liver. ADF also suppressed lipid accumulation by inactivating the expression of peroxisome proliferator-activated receptor gamma (PPAR-γ) and sterol regulatory element-binding protein-1c (SREBP-1c). Furthermore, ADF elevated the expression of fibroblast growth factor 21 (FGF21) and down-stream signaling AMPK/silent mating type information regulation 2 homolog 1 (SIRT1)/peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) in the liver of diabetic mice. The mitochondrial biogenesis and autophagy were also stimulated by ADF. Interestingly, ADF also enhanced the bile acids (BAs) metabolism by generating more cholic acid (CA), deoxycholic acid (DCA) and tauroursodeoxycholic acid (TUDCA) in db/db mice. In conclusion, ADF could significantly inhibit T2D induced insulin resistance and obesity, promote insulin signaling，reduce inflammation, as well as promote glycogen synthesis and lipid metabolism. It possibly depends on FGF21 and BA metabolism to enhance mitochondrial biosynthesis and energy metabolism.