Synthesis of MPEG-b-PLLA Diblock Copolymers and Their Crystallization Performance with PDLA and PLLA Composite Films.

Methoxy poly(ethylene glycol)-block-poly(L-lactide) (MPEG-b-PLLA) has a wide range of applications in pharmaceuticals and biology, and its structure and morphology have been thoroughly studied. In the experiment, we synthesized MPEG-b-PLLA with different block lengths using the principle of ring-opening polymerization by controlling the amount of lactic acid added. The thermodynamic properties of copolymers and the crystallization properties of blends were studied separately. The crystallization kinetics of PDLA/MPEG-b-PLA and PLLA/MPEG-b-PLA composite films were studied using differential scanning calorimetry (DSC). The results indicate that the crystallization kinetics of composite films are closely related to the amount of block addition. The crystallinity of the sample first increases and then decreases with an increase in MPEG-b-PLLA content. These results were also confirmed in polarized optical microscope (POM) and wide-angle X-ray diffraction (WAXD) tests. When 3% MPEG-b-PLLA was added to the PDLA matrix, the blend exhibited the strongest crystallization performance.

Cancer screening in hospitalized ischemic stroke patients: a multicenter study focused on multiparametric analysis to improve management of occult cancers.

Background/aims: The reciprocal promotion of cancer and stroke occurs due to changes in shared risk factors, such as metabolic pathways and molecular targets, creating a "vicious cycle." Cancer plays a direct or indirect role in the pathogenesis of ischemic stroke (IS), along with the reactive medical approach used in the treatment and clinical management of IS patients, resulting in clinical challenges associated with occult cancer in these patients. The lack of reliable and simple tools hinders the effectiveness of the predictive, preventive, and personalized medicine (PPPM/3PM) approach. Therefore, we conducted a multicenter study that focused on multiparametric analysis to facilitate early diagnosis of occult cancer and personalized treatment for stroke associated with cancer. Methods: Admission routine clinical examination indicators of IS patients were retrospectively collated from the electronic medical records. The training dataset comprised 136 IS patients with concurrent cancer, matched at a 1:1 ratio with a control group. The risk of occult cancer in IS patients was assessed through logistic regression and five alternative machine-learning models. Subsequently, select the model with the highest predictive efficacy to create a nomogram, which is a quantitative tool for predicting diagnosis in clinical practice. Internal validation employed a ten-fold cross-validation, while external validation involved 239 IS patients from six centers. Validation encompassed receiver operating characteristic (ROC) curves, calibration curves, decision curve analysis (DCA), and comparison with models from prior research. Results: The ultimate prediction model was based on logistic regression and incorporated the following variables: regions of ischemic lesions, multiple vascular territories, hypertension, D-dimer, fibrinogen (FIB), and hemoglobin (Hb). The area under the ROC curve (AUC) for the nomogram was 0.871 in the training dataset and 0.834 in the external test dataset. Both calibration curves and DCA underscored the nomogram's strong performance. Conclusions: The nomogram enables early occult cancer diagnosis in hospitalized IS patients and helps to accurately identify the cause of IS, while the promotion of IS stratification makes personalized treatment feasible. The online nomogram based on routine clinical examination indicators of IS patients offered a cost-effective platform for secondary care in the framework of PPPM. Supplementary Information: The online version contains supplementary material available at 10.1007/s13167-024-00354-8.

Zinc finger protein ZNF638 regulates triglyceride metabolism via ANGPTL8 in an estrogen dependent manner.

BACKGROUND AND AIM: Triglyceride (TG) levels are closely related to obesity, fatty liver and cardiovascular diseases, while the regulatory factors and mechanism for triglyceride homeostasis are still largely unknown. Zinc Finger Protein 638 (ZNF638) is a newly discovered member of zinc finger protein family for adipocyte function in vitro. The aim of the present work was to investigate the role of ZNF638 in regulating triglyceride metabolism in mice. METHODS: We generated ZNF638 adipose tissue specific knockout mice (ZNF638 FKO) by cross-breeding ZNF638 flox to Adiponectin-Cre mice and achieved adipose tissue ZNF638 overexpression via adenoviral mediated ZNF638 delivery in inguinal adipose tissue (iWAT) to examined the role and mechanisms of ZNF638 in fat biology and whole-body TG homeostasis. RESULTS: Although ZNF638 FKO mice showed similar body weights, body composition, glucose metabolism and serum parameters compared to wild-type mice under chow diet, serum TG levels in ZNF638 FKO mice were increased dramatically after refeeding compared to wild-type mice, accompanied with decreased endothelial lipoprotein lipase (LPL) activity and increased lipid absorption of the small intestine. Conversely, ZNF638 overexpression in iWAT reduced serum TG levels while enhanced LPL activity after refeeding in female C57BL/6J mice and obese ob/ob mice. Specifically, only female mice exhibited altered TG metabolism upon ZNF638 expression changes in fat. Mechanistically, RNA-sequencing analysis revealed that the TG regulator angiopoietin-like protein 8 (Angptl8) was highly expressed in iWAT of female ZNF638 FKO mice. Neutralizing circulating ANGPTL8 in female ZNF638 FKO mice abolished refeeding-induced TG elevation. Furthermore, we demonstrated that ZNF638 functions as a transcriptional repressor by recruiting HDAC1 for histone deacetylation and broad lipid metabolic gene suppression, including Angptl8 transcription inhibition. Moreover, we showed that the sexual dimorphism is possibly due to estrogen dependent regulation on ZNF638-ANGPTL8 axis. CONCLUSION: We revealed a role of ZNF638 in the regulation of triglyceride metabolism by affecting Angptl8 transcriptional level in adipose tissue with sexual dimorphism.

Characterisation of forkhead box protein A3 as a key transcription factor for hepatocyte regeneration.

Background & Aims: Liver regeneration is vital for the recovery of liver function after injury, yet the underlying mechanism remains to be elucidated. Forkhead box protein A3 (FOXA3), a member of the forkhead box family, plays important roles in endoplasmic reticulum stress sensing, and lipid and glucose homoeostasis, yet its functions in liver regeneration are unknown. Methods: Here, we explored whether Foxa3 regulates liver regeneration via acute and chronic liver injury mice models. We further characterised the molecular mechanism by chromatin immunoprecipitation sequencing and rescue experiments in vivo and in vitro. Then, we assessed the impact of Foxa3 pharmacological activation on progression and termination of liver regeneration. Finally, we confirmed the Foxa3-Cebpb axis in human liver samples. Results: Foxa3 is dominantly expressed in hepatocytes and cholangiocytes and is induced upon partial hepatectomy (PH) or carbon tetrachloride (CCl4) administration. Foxa3 deficiency in mice decreased cyclin gene levels and delayed liver regeneration after PH, or acute or chronic i.p. CCl4 injection. Conversely, hepatocyte-specific Foxa3 overexpression accelerated hepatocytes proliferation and attenuated liver damage in an CCl4-induced acute model. Mechanistically, Foxa3 directly regulates Cebpb transcription, which is involved in hepatocyte division and apoptosis both in vivo and in vitro. Of note, Cebpb overexpression in livers of Foxa3-deficient mice rescued their defects in cell proliferation and regeneration upon CCl4 treatment. In addition, pharmacological induction of Foxa3 via cardamonin speeded up hepatocyte proliferation after PH, without interfering with liver regeneration termination. Finally, Cebpb and Ki67 levels had a positive correlation with Foxa3 expression in human chronic disease livers. Conclusions: These data characterise Foxa3 as a vital regulator of liver regeneration, which may represent an essential factor to maintain liver mass after liver injury by governing Cebpb transcription. Impact and Implications: Liver regeneration is vital for the recovery of liver function after chemical insults or hepatectomy, yet the underlying mechanism remains to be elucidated. Herein, via in vitro and in vivo models and analysis, we demonstrated that Forkhead box protein A3 (FOXA3), a Forkhead box family member, maintained normal liver regeneration progression by governing Cebpb transcription and proposed cardamonin as a lead compound to induce Foxa3 and accelerate liver repair, which signified that FOXA3 may be a potential therapeutic target for further preclinical study on treating liver injury.

AAV-Mediated nuclear localized PGC1α4 delivery in muscle ameliorates sarcopenia and aging-associated metabolic dysfunctions.

Sarcopenia is characterized of muscle mass loss and functional decline in elder individuals which severely affects human physical activity, metabolic homeostasis, and life quality. Physical exercise is considered effective in combating muscle atrophy and sarcopenia, yet it is not feasible to elders with limited mobility. PGC-1α4, a short isoform of PGC-1α, is strongly induced in muscle under resistance training, and promotes muscle hypertrophy. In the present study, we showed that the transcriptional levels and nuclear localization of PGC1α4 was reduced during aging, accompanied with muscle dystrophic morphology, and gene programs. We thus designed NLS-PGC1α4 and ectopically express it in myotubes to enhance PGC1α4 levels and maintain its location in nucleus. Indeed, NLS-PGC1α4 overexpression increased muscle sizes in myotubes. In addition, by utilizing AAV-NLS-PGC1α4 delivery into gastrocnemius muscle, we found that it could improve sarcopenia with grip strength, muscle weights, fiber size and molecular phenotypes, and alleviate age-associated adiposity, insulin resistance and hepatic steatosis, accompanied with altered gene signatures. Mechanistically, we demonstrated that NLS-PGC-1α4 improved insulin signaling and enhanced glucose uptake in skeletal muscle. Besides, via RNA-seq analysis, we identified myokines IGF1 and METRNL as potential targets of NLS-PGC-1α4 that possibly mediate the improvement of muscle and adipose tissue functionality and systemic energy metabolism in aged mice. Moreover, we found a negative correlation between PGC1α4 and age in human skeletal muscle. Together, our results revealed that NLS-PGC1α4 overexpression improves muscle physiology and systematic energy homeostasis during aging and suggested it as a potent therapeutic strategy against sarcopenia and aging-associated metabolic diseases.

Recent advances in enhancing stereocomplexation between poly(lactide) enantiomeric chains.

Over the past three decades, its excellent biodegradability and biocompatibility have enabled poly(lactide) (PLA) to be extensively explored as a replacement for oil-based thermoplastics in biomedical and industrial applications. However, PLA homopolymers have "facilitative" limitations such as low mechanical properties, low processing temperatures, slow recrystallization, and insufficient crystallinity, which have usually hindered commercial PLA in industrial and biomedical applications. The formation of stereo-complexation between enantiomeric poly(L-lactide) (PLLA) and poly(D-lactide) (PDLA) chains offers an effective approach to PLA-based engineering materials with improved properties. In this review, we have understandably summarized recent progress in improving the SC crystallization of PLA-based plastics into two aspects, i.e., enantiomeric PLA homopolymers, and enantiomeric PLA-based copolymers. One important point to be noted is that much emphasis is focused on improving SC crystallization by enhancing interactions in the enantiomeric PLA-based copolymers. There is an insightful discussion about the effect of enhanced SC crystallization as well as intermolecular interactions between PLLA and PDLA chains in various stereocomplexable systems. Most importantly, this review starts with the basic understanding of SC crystallization and further elaborates on the rational mechanism of enhanced SC crystallization to provide a broad idea for broadening the road toward PLA-based materials.

Neuregulin4 Acts on Hypothalamic ErBb4 to Excite Oxytocin Neurons and Preserve Metabolic Homeostasis.

Neuregulin 4 (Nrg4) is an adipose tissue-enriched secreted factor that modulates glucose and lipid metabolism. Nrg4 is closely associated with obesity and preserves diet-induced metabolic disorders. However, the specific mechanisms via which Nrg4 regulates metabolic homeostasis remain incompletely understood. Here, this work finds that the Nrg4 receptor, ErbB4, is highly expressed in the hypothalamus, and the phosphorylation of hypothalamic ErbB4 is reduced in diet-induced obesity (DIO) mice. Peripheral Nrg4 can act on ErbB4 via blood circulation and excite neurons in the paraventricular nucleus of hypothalamus (PVN). Central administration of recombinant Nrg4 protein (rNrg4) reduces obesity and related metabolic disorders by influencing energy expenditure and intake. Overexpression of ErbB4 in the PVN protects against obesity, whereas its knock down in oxytocin (Oxt) neuron accelerates obesity. Furthermore, Nrg4-ErbB4 signaling excites Oxt release, and ablation of Oxt neuron considerably attenuates the effect of Nrg4 on energy balance. These data suggest that the hypothalamus is a key target of Nrg4, which partially explains the multifaceted roles of Nrg4 in metabolism.

Irisin ameliorates age-associated sarcopenia and metabolic dysfunction.

BACKGROUND: Age-associated sarcopenia is characterized of progressed loss of skeletal muscle power, mass, and function, which affects human physical activity and life quality. Besides, accompanied with sarcopenia, aged population also faces a series of metabolic dysfunctions. Irisin, the cleaved form of fibronectin type III domain-containing protein 5 (FNDC5), is a myokine induced by exercise and has been shown to exert multiple beneficial effects on health. The goal of the study is to investigate the alterations of Fndc5/irisin in skeletal muscles during ageing and whether irisin administration could ameliorate age-associated sarcopenia and metabolic dysfunction. METHODS: The mRNA and protein levels of FNDC5/irisin in skeletal muscle and serum from 2- and 24-month-old mice or human subjects were analysed using qRT-PCR and western blot. FNDC5/irisin knockout mice were generated to investigate the consequences of FNDC5/irisin deletion on skeletal muscle mass, as well as morphological and molecular changes in muscle during ageing via histological and molecular analysis. To identify the therapeutic effects of chronic irisin treatment in mice during ageing, in vivo intraperitoneal administration of 2 mg/kg recombinant irisin was performed three times per week in ageing mice (14-month-old) for 4 months or in aged mice (22-month-old) for 1 month to systematically investigate irisin's effects on age-associated sarcopenia and metabolic performances, including grip strength, body weights, body composition, insulin sensitivity, energy expenditure, serum parameters and phenotypical and molecular changes in fat and liver. RESULTS: We showed that the expression levels of irisin, as well as its precursor Fndc5, were reduced at mRNA and protein expression levels in muscle during ageing. In addition, via phenotypic analysis of FNDC5/irisin knockout mice, we found that FNDC5/irisin deficiency in aged mice exhibited aggravated muscle atrophy including smaller grip strength (-3.23%, P < 0.05), muscle weights (quadriceps femoris [QU]: -20.05%; gastrocnemius [GAS]: -17.91%; tibialis anterior [TA]: -19.51%, all P < 0.05), fibre size (QU: P < 0.01) and worse molecular phenotypes compared with wild-type mice. We then delivered recombinant irisin protein intraperitoneally into ageing or aged mice and found that it could improve sarcopenia with grip strength (+18.42%, P < 0.01 or +13.88%, P < 0.01), muscle weights (QU: +9.02%, P < 0.01 or +16.39%, P < 0.05), fibre size (QU: both P < 0.05) and molecular phenotypes and alleviated age-associated fat tissues expansion, insulin resistance and hepatic steatosis (all P < 0.05), accompanied with altered gene signatures. CONCLUSIONS: Together, this study revealed the importance of irisin in the maintenance of muscle physiology and systematic energy homeostasis during ageing and suggested a potent therapeutic strategy against age-associated metabolic diseases via irisin administration.

Role of the Branched PEG-b-PLLA Block Chain in Stereocomplex Crystallization and Crystallization Kinetics for PDLA/MPEG-b-PLLA-g-glucose Blends with Different Architectures.

The isothermal crystallization behavior and corresponding morphology evolution of poly(d-lactic acid) (PDLA) blends with PLLA6.7k or MPEG-b-PLLA6.7k-g-glucose with different architectures and different PLLA-grafted copolymer contents were investigated. The formation of stereocomplexes (SCs) in between the chain branched structure of MPEG-b-PLLA6.7k-g-glucose and PDLA chains acting as the physical crosslinking points slows down the motion of PDLA chains, but the SCs could act as a heterogeneous nucleating agent for the late formation of homocrystals (HCs) in the blend system, accelerating the crystallization kinetics of HCs through enhancing the nucleation density. For PDLA/MPEG-b-PLLA6.7k-g-glucose blends, the mobility of SCs in the blend system and the nucleation density of SCs in the blends exhibit oppositional behavior during the isothermal crystallization at a Tc of 130 °C. The evolution of the crystal growth and structure during the isothermal crystallization process by rheometry has revealed the interesting role of the branched chains of MPEG-b-PLLA6.7k-g-glucose in the mechanism of the crystallization in PDLA blends.

Competitive Mechanism of Stereocomplexes and Homocrystals in High-Performance Symmetric and Asymmetric Poly(lactic acid) Enantiomers: Qualitative Methods.

To systematically explore the critical contributions of both molecular weights and crystallization temperature and chain length and molar ratios to the formation of stereocomplexes (SCs), our group quantitatively prepared a wide MW range of symmetric and asymmetric poly(lactic acid) (PLA) racemic blends, which contains L-MW PLLA with M n > 6k g/mol. The crystallinity and relative fraction of SCs increase with T c, and the SCs are exclusively formed at T c > 180 °C in M/H-MW racemic blends. When MWs of one of the enantiomers are over 6k and less than 41k, multiple stereocomplexation is clear in the asymmetric racemic blends and more ordered SCs form with less entanglement or the amorphous region compared to those for the MW of the enantiomers over 41k in the symmetric/asymmetric enantiomers. When the MW of the blends is more than 41k, SCs and homocrystals (HCs) coexist in the symmetric enantiomers and the multicomplexation can restrict the asymmetric enantiomers. This study provides a deep comprehensive insight into the stereocomplex crystallization mechanism of polymers and provides a reference value for future research attempting to prepare stereocomplex materials.

The effects of weathering of coal-bearing stratum on the transport and transformation of DIC in karst watershed.

The mining of medium- to high­sulfur coal in karst areas has led to serious acidification problems in surface water, thus encouraging a re-evaluation of DIC transformation and CO2 source-sink relationships in karst watersheds. The weathering of limestone and sulfide-rich coal measures jointly influence the pH of the Huatan River in karst areas in Southwest China, which is lower in the rainy season and higher in the dry season. Due to CO2 degassing, DIC concentration tends to decrease along the flow direction, while δ13C-DIC gradually becomes heavier. In general, DIC transformation in the Huatan River is controlled by AMD input, CO2 degassing, organic matter (OM) degradation, and the dissolution and precipitation balance of carbonate minerals in different seasons. In spring, the mineralization of OM from terrestrial and domestic sewage gradually enhances and replenishes DIC in the water. As the pH increases in this season, the capacity for buffering CO2 increases. Meanwhile, OM degradation generates a large amount of CO2 in summer, and carbonic acid begins to dissolve limestone. In autumn, the pH decreases due to the enhanced weathering of sulfide-rich coal measures and the mass input of AMD. Thus, the river shows the ability to drive CO2 outgassing. In winter, CO2 degassing gradually weakens, DIC concentration is at its lowest, and δ13C-DIC reaches the heaviest value.

Local hyperthermia therapy induces browning of white fat and treats obesity.

Beige fat plays key roles in the regulation of systemic energy homeostasis; however, detailed mechanisms and safe strategy for its activation remain elusive. In this study, we discovered that local hyperthermia therapy (LHT) targeting beige fat promoted its activation in humans and mice. LHT achieved using a hydrogel-based photothermal therapy activated beige fat, preventing and treating obesity in mice without adverse effects. HSF1 is required for the effects since HSF1 deficiency blunted the metabolic benefits of LHT. HSF1 regulates Hnrnpa2b1 (A2b1) transcription, leading to increased mRNA stability of key metabolic genes. Importantly, analysis of human association studies followed by functional analysis revealed that the HSF1 gain-of-function variant p.P365T is associated with improved metabolic performance in humans and increased A2b1 transcription in mice and cells. Overall, we demonstrate that LHT offers a promising strategy against obesity by inducing beige fat activation via HSF1-A2B1 transcriptional axis.

Comprehensive Transcriptome Profiling of NAFLD- and NASH-Induced Skeletal Muscle Dysfunction.

Nonalcoholic fatty liver disease (NAFLD), characterized by extensive triglyceride accumulation in hepatocytes, may progress to nonalcoholic steatohepatitis (NASH) with liver fibrosis and inflammation and increase the risk of cirrhosis, cancer, and death. It has been reported that physical exercise is effective in ameliorating NAFLD and NASH, while skeletal muscle dysfunctions, including lipid deposition and weakness, are accompanied with NAFLD and NASH. However, the molecular characteristics and alterations in skeletal muscle in the progress of NAFLD and NASH remain unclear. In the present study, we provide a comprehensive analysis on the similarity and heterogeneity of quadriceps muscle in NAFLD and NASH mice models by RNA sequencing. Importantly, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway functional enrichment analysis revealed that NAFLD and NASH led to impaired glucose and lipid metabolism and deteriorated functionality in skeletal muscle. Besides this, we identified that myokines possibly mediate the crosstalk between muscles and other metabolic organs in pathological conditions. Overall, our analysis revealed a comprehensive understanding of the molecular signature of skeletal muscles in NAFLD and NASH, thus providing a basis for physical exercise as an intervention against liver diseases.

Antibiotic Azithromycin inhibits brown/beige fat functionality and promotes obesity in human and rodents.

Obesity, a metabolic disease caused by multiple factors, has become a global health problem. In addition to nutrient intake and sedentary lifestyle, environmental pollutants exposure has been shown to be involved in obesity epidemics. Antibiotics, a new type of environmental pollutant, have been widely used in animal husbandry, aquaculture and microorganism. However, the effects of antibiotics exposure on fat metabolism and metabolic diseases are largely unknown. Methods: We screened major types of antibiotics to examine their effects on the differentiation capacity and thermogenic functionality of brown and beige adipocytes, and found that azithromycin, one major kind of macrolide antibiotics suppressed brown and beige adipocyte functionality. We thus examined azithromycin accretion in adipose tissues of obese patients that correlates with BMI by high performance liquid chromatography-tandem mass spectrometry and systematically explore the influences of azithromycin on adiposity and metabolic performance in mice under high diet. Results: Azithromycin (macrolides) inhibits the mitochondrial and thermogenic gene programs of brown and beige adipocytes, thus disrupting their mitochondrial function and thermogenic response. Consistently, azithromycin treatment are more prone to diet-induced obesity in mice, and this was associated with impaired energy expenditure. Importantly, azithromycin is more accumulated in adipose tissue of obese patients and correlates with BMI and body weight. Mechanistically, we found that azithromycin inhibits mitochondria respiratory complex I protein levels and increases reactive oxidative species (ROS) levels, which causes damage of mitochondrial function in brown and beige adipocytes. The deleterious effects of azithromycin can be ameliorated by antioxidant N-acetyl-L-cysteine. Conclusions: Taken together, this work highlights the possible role of azithromycin in obesity epidemic and presents strategies for safe applications of antibiotics in the future.

Synthesis and Properties of Nitrogen-Doped Carbon Quantum Dots Using Lactic Acid as Carbon Source.

Nitrogen-doped carbon quantum dots (N-CQDs) were synthesized in a one-step hydrothermal technique utilizing L-lactic acid as that of the source of carbon and ethylenediamine as that of the source of nitrogen, and were characterized using dynamic light scattering, X-ray photoelectron spectroscopy ultraviolet-visible spectrum, Fourier-transformed infrared spectrum, high-resolution transmission electron microscopy, and fluorescence spectrum. The generated N-CQDs have a spherical structure and overall diameters ranging from 1-4 nm, and their surface comprises specific functional groups such as amino, carboxyl, and hydroxyl, resulting in greater water solubility and fluorescence. The quantum yield of N-CQDs (being 46%) is significantly higher than that of the CQDs synthesized from other biomass in literatures. Its fluorescence intensity is dependent on the excitation wavelength, and N-CQDs release blue light at 365 nm under ultraviolet light. The pH values may impact the protonation of N-CQDs surface functional groups and lead to significant fluorescence quenching of N-CQDs. Therefore, the fluorescence intensity of N-CQDs is the highest at pH 7.0, but it decreases with pH as pH values being either more than or less than pH 7.0. The N-CQDs exhibit high sensitivity to Fe3+ ions, for Fe3+ ions would decrease the fluorescence intensity of N-CQDs by 99.6%, and the influence of Fe3+ ions on N-CQDs fluorescence quenching is slightly affected by other metal ions. Moreover, the fluorescence quenching efficiency of Fe3+ ions displays an obvious linear relationship to Fe3+ concentrations in a wide range of concentrations (up to 200 µM) and with a detection limit of 1.89 µM. Therefore, the generated N-CQDs may be utilized as a robust fluorescence sensor for detecting pH and Fe3+ ions.

Combination Usage of AdipoCount and Image-Pro Plus/ImageJ Software for Quantification of Adipocyte Sizes.

In recent decades, the prevalence of obesity has been rising. One of the major characteristics of obesity is fat accumulation, including hyperplasia (increase in number) and hypertrophy (increase in size). After histological staining, it is critical to accurately measure the number and size of adipocytes for assessing the severity of obesity in a timely fashion. Manual measurement is accurate but time-consuming. Although commercially available adipocyte counting tools, including AdipoCount, Image-Pro Plus, and ImageJ were helpful, limitations still exist in accuracy and time consuming. In the present study, we introduced the protocol of combined usage of these tools and illustrated the process with histological staining slides from adipose tissues of lean and obese mice. We found that the adipocyte sizes quantified by the tool combination were comparable as manual measurement, whereas the combined methods were more efficient. Besides, the recognition effect of monochrome segmentation image is better than that of color segmentation image. Overall, we developed a combination method to measure adipocyte sizes accurately and efficiently, which may be helpful for experimental process in laboratory and also for clinic diagnosis.

Diel variation of CH4 emission fluxes in a small artificial lake: Toward more accurate methods of observation.

Lakes are significant sources in global methane (CH4) budgets. However, estimations of the magnitude of global CH4 emissions from lakes may be highly biased owing to the uncertainties in data originating from observation times, methods, and parameterizations of the gas transfer velocity (k). Here, we conducted continuous 48-hour measurements of CH4 fluxes using the floating chamber method seasonally at Lake Baihua, a small reservoir in southwestern China, and compared the results with estimates derived from boundary layer models. Results showed that there was a weak dependency of k on wind speed, indicating that wind speed was not the major factor regulating gas exchange in such small lakes. It is thus concluded that the wind speed-dependent boundary layer model method is not suitable for CH4 flux observations in small and medium-sized lake, and that the floating chamber method is recommended for use instead. The measured CH4 fluxes displayed remarkably diurnal patterns, therefore the use of single observations to represent daily average values comes with unacceptably large uncertainties. A reasonable alternative is averaging observations made at sunrise and at sunset to represent daily values, which has a much smaller uncertainty (ranging from 0.8% to 13.6%). The coincident peaks of CH4 and chlorophyll concentrations in the subsurface indicate that CH4 originated mainly from aerobic methanogenesis. Solar radiation is likely one of the major factors regulating CH4 production and emissions in the lake through enhancing CH4 production, inhibiting CH4 oxidation, and probably changing hydrodynamics conditions. Therefore, irradiation should be taken into consideration as a key factor in observing CH4 fluxes in lakes. As sampling times are limited, observations during both sunny and cloudy weather should be proportionally included. This is the first time, to the best of our knowledge, that solar radiation has been proposed as a key driver of CH4 emissions from lakes.

A fluorometric and colorimetric approach for the rapid detection of berberine hydrochloride based on an anionic polythiophene derivative.

In this report, we develop a dual-output sensor with fluorometric and colorimetric responses, for the rapid and simple detection of berberine hydrochloride (BRH) in 100% aqueous solution based on an anionic polythiophene derivative, poly(2-(2-(4-methylthiophen-3-yloxy)-ethyl) malonic acid) (PTMA). The sensing performance and mechanism were carefully examined by absorption and emission spectra. It can be applied to quantitatively detect BRH in aqueous solution with a detection limit 0.27 µM. The appealing performance of the sensor was demonstrated to originate from the electrostatic and π-π interactions between PTMA and BRH, which promoted the conformational change and aggregation of the PTMA backbone. Moreover, this method allowed rapid detection of BRH in urine samples and BRH tablets with high accuracy.

Autonomous climbing: An effective exercise mode with beneficial outcomes of aerobic exercise and resistance training.

AIMS: To assess the effects of three specific exercise training modes, aerobic exercise (A), resistance training (R) and autonomous climbing (AC), aimed at proposing a cross-training method, on improving the physical, molecular and metabolic characteristics of mice without many side effects. MATERIALS AND METHODS: Seven-week-old male mice were randomly divided into four groups: control (C), aerobic exercise (A), resistance training (R), and autonomous climbing (AC) groups. Physical changes in mice were tracked and analysed to explore the similarities and differences of these three exercise modes. Histochemistry, quantitative real-time PCR (RT-PCR), western blot (WB) and metabolomics analysis were performed to identify the underlying relationships among the three training modes. KEY FINDINGS: Mice in the AC group showed better body weight control, glucose and energy homeostasis. Molecular markers of myogenesis, hypertrophy, antidegradation and mitochondrial function were highly expressed in the muscle of mice after autonomous climbing. The serum metabolomics landscape and enriched pathway comparison indicated that the aerobic oxidation pathway (pentose phosphate pathway, galactose metabolism and fatty acid degradation) and amino acid metabolism pathway (tyrosine, arginine and proline metabolism) were significantly enriched in group AC, suggesting an increased muscle mitochondrial function and protein balance ability of mice after autonomous climbing. SIGNIFICANCE: We propose a new exercise mode, autonomous climbing, as a convenient but effective training method that combines the beneficial effects of aerobic exercise and resistance training.

PPARγ agonists delay age-associated metabolic disease and extend longevity.

Aging leads to a number of disorders caused by cellular senescence, tissue damage, and organ dysfunction. It has been reported that anti-inflammatory and insulin-sensitizing compounds delay, or reverse, the aging process and prevent metabolic disorders, neurodegenerative disease, and muscle atrophy, improving healthspan and extending lifespan. Here we investigated the effects of PPARγ agonists in preventing aging and increasing longevity, given their known properties in lowering inflammation and decreasing glycemia. Our molecular and physiological studies show that long-term treatment of mice at 14 months of age with low doses of the PPARγ ligand rosiglitazone (Rosi) improved glucose metabolism and mitochondrial functionality. These effects were associated with decreased inflammation and reduced tissue atrophy, improved cognitive function, and diminished anxiety- and depression-like conditions, without any adverse effects on cardiac and skeletal functionality. Furthermore, Rosi treatment of mice started when they were 14 months old was associated with lifespan extension. A retrospective analysis of the effects of the PPARγ agonist pioglitazone (Pio) on longevity showed decreased mortality in patients receiving Pio compared to those receiving a PPARγ-independent insulin secretagogue glimepiride. Taken together, these data suggest the possibility of using PPARγ agonists to promote healthy aging and extend lifespan.