Engineering a Carotenoid Cleavage Oxygenase for Coenzyme-Free Synthesis of Vanillin from Ferulic Acid

One-pot biosynthesis of vanillin from ferulic acid without providing energy and cofactors adds significant value to lignin waste streams. However, naturally evolved carotenoid cleavage oxygenase (CCO) with extreme catalytic conditions greatly limited the above pathway for vanillin bioproduction. Herein, CCO from Thermothelomyces thermophilus (TtCCO) was rationally engineered for achieving high catalytic activity under neutral pH conditions and was further utilized for constructing a one-pot synthesis system of vanillin with Bacillus pumilus ferulic acid decarboxylase. TtCCO with the K192N-V310G-A311T-R404N-D407F-N556A mutation (TtCCOM3) was gradually obtained using substrate access channel engineering, catalytic pocket engineering, and pocket charge engineering. Molecular dynamics simulations revealed that reducing the site-blocking effect in the substrate access channel, enhancing affinity for substrates in the catalytic pocket, and eliminating the pocket's alkaline charge contributed to the high catalytic activity of TtCCOM3 under neutral pH conditions. Finally, the one-pot synthesis of vanillin in our study could achieve a maximum rate of up to 6.89 ± 0.3 mM h-1. Therefore, our study paves the way for a one-pot biosynthetic process of transforming renewable lignin-related aromatics into valuable chemicals.

Hydroxytyrosol Alleviates Obesity-Induced Cognitive Decline by Modulating the Expression Levels of Brain-Derived Neurotrophic Factors and Inflammatory Factors in Mice

Hydroxytyrosol (HT; 3,4-dihydroxyphenyl ethanol) is an important functional polyphenol in olive oil. Our study sought to evaluate the protective effects and underlying mechanisms of HT on obesity-induced cognitive impairment. A high-fat and high-fructose-diet-induced obese mice model was treated with HT for 14 weeks. The results show that HT improved the learning and memory abilities and enhanced the expressions of brain-derived neurotrophic factors (BDNFs) and postsynaptic density proteins, protecting neuronal and synaptic functions in obese mice. Transcriptomic results further confirmed that HT improved cognitive impairment by regulating gene expression in neural system development and synaptic function-related pathways. Moreover, HT treatment alleviated neuroinflammation in the brain of obese mice. To sum up, our results indicated that HT can alleviate obesity-induced cognitive dysfunction by enhancing BDNF expression and alleviating neuroinflammation in the brain, which also means that HT may become a potentially useful nutritional supplement to alleviate obesity-induced cognitive decline.

[Intervention effect of apocynin on silicosis induced by silica in rats]

Objective: To investigate the intervention effect and its mechanism of apocynin, an inhibitor of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) on silicosis induced by silica (SiO(2)) in rats. Methods: In October 2021, 24 SPF SD male rats were divided into control group, silicosis model group and apocynin intervention group according to random number table method, with 8 rats in each group. SiO(2) was exposed by one-time intratracheal instillation. The rats in the apocynin intervention group were intraperitoneally injected with apocynin 50 mg/kg, 3 times a week, on the second day after treatment. The rats were sacrificed 28 days later, and lung coefficients were calculated after lung tissues were weighed. Hematoxylin-eosin staining and Masson staining were used to observe the lung histopathological changes in each group, respectively. The levels of NOX, reactive oxygen species (ROS), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) in lung tissue were detected. The expressions of interleukin-1 beta (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) were determined by Enzyme-Linked Immunosorbent Assay (ELISA). The level of hydroxyproline (HYP) was detected by alkaline hydrolysate. The expressions of transforming growth factor beta 1 (TGF-β1), E-cadherin (E-cad) and α-smooth muscle actin (α-SMA) in lung tissue were detected by Western blotting. Results: Compared with the control group, the body weight of silicosis model group was decreased, the lung tissue showed obvious inflammatory infiltration and fibrosis, and the levels of lung coefficient, IL-1β, IL-6, TNF-α and TGF-β1 were significantly increased (P<0.05). Compared with the silicosis model group, the lung tissue injury in the apocynin intervention group was significantly improved, the lung coefficient, NOX, ROS, MDA, IL-1β, IL-6, TNF-α and TGF-β1 levels were decreased, and the activity of GSH-Px was increased (P<0.05). Compared with the silicosis model group, the expressions of HYP and α-SMA were decreased and the level of E-cad was increased in the apocynin intervention group (P<0.05) . Conclusion: Apocynin may alleviate SiO(2)-induced fibrosis in silicosis rats by reducing oxidative stress, the release of inflammatory factors and inhibiting the process of epithelial-mesenchymal transition.

Characterization of an efficient CRISPR-iCas9 system in Yarrowia lipolytica for the biosynthesis of carotenoids

The application of clustered regularly interspaced short palindromic repeats-Cas (CRISPR-Cas9) technology in the genetic modification of Yarrowia lipolytica is challenged by low efficiency and low throughput. Here, a highly efficient CRISPR-iCas9 (with D147Y and P411T mutants) genetic manipulation tool was established for Y. lipolytica, which was further utilized to integrate carotene synthetic key genes and significantly improve the target product yield. First, CRISPR-iCas9 could shorten the time of genetic modification and enable the rapid knockout of nonsense suppressors. iCas9 can lead to more than 98% knockout efficiency for NHEJ-mediated repair after optimal target disruption of a single gene, 100% knockout efficiency for a single gene-guided version, and more than 80% knockout efficiency for multiple genes simultaneously in Y. lipolytica. Subsequently, this technology allowed for rapid one-step integration of large fragments (up to 9902-bp) of genes into chromosomes. Finally, YL-ABTG and YL-ABTG2Z were further constructed through CRISPR-iCas9 integration of key genes in a one-step process, resulting in a maximum β-carotene and zeaxanthin content of 3.12 mg/g and 2.33 mg/g dry cell weight, respectively. Therefore, CRISPR-iCas9 technology provides a feasible approach to genetic modification for efficient biosynthesis of biological compounds in Y. lipolytica. KEY POINTS: • iCas9 with D147Y and P411T mutants improved the CRISPR efficiency in Y. lipolytica. • CRISPR-iCas9 achieved efficient gene knockout and integration in Y. lipolytica. • CRISPR-iCas9 rapidly modified Y. lipolytica for carotenoid bioproduction.

MDFI regulates fast-to-slow muscle fiber type transformation via the calcium signaling pathway

Muscle fiber is the basic unit of skeletal muscle with strong self-adaptability, and its type is closely related to meat quality. Myod family inhibitor (Mdfi) has the function of regulating myogenic regulatory factors during cell differentiation, but how Mdfi regulates muscle fiber type transformation in myoblasts is still unclear. In the present study, we constructed overexpressing and interfering with Mdfi C2C12 cell models by lipofection. The immunofluorescence, quantitative real-time PCR (qPCR), and western blot results show that the elevated MDFI promoted mitochondrial biogenesis, aerobic metabolism and the calcium level by activating CaMKK2 and AMPK phosphorylation and then stimulated the conversion of C2C12 cells from fast glycolytic to slow oxidative type. In addition, after inhibiting IP3R and RYR channels, the higher MDFI reversed the blockage of calcium release from the endoplasmic reticulum by calcium channel receptor inhibitors and increased intracellular calcium levels. Therefore, we propose that the higher MDFI promotes muscle fiber types conversion through the calcium signaling pathway. These findings further broaden our understanding of the regulatory mechanism of MDFI in muscle fiber type transformation. Furthermore, our results suggest potential therapeutic targets for skeletal muscle and metabolic-related diseases.

pH-dependent water permeability switching and its memory in MoS2 membranes

Intelligent transport of molecular species across different barriers is critical for various biological functions and is achieved through the unique properties of biological membranes1-4. Two essential features of intelligent transport are the ability to (1) adapt to different external and internal conditions and (2) memorize the previous state5. In biological systems, the most common form of such intelligence is expressed as hysteresis6. Despite numerous advances made over previous decades on smart membranes, it remains a challenge to create a synthetic membrane with stable hysteretic behaviour for molecular transport7-11. Here we demonstrate the memory effects and stimuli-regulated transport of molecules through an intelligent, phase-changing MoS2 membrane in response to external pH. We show that water and ion permeation through 1T' MoS2 membranes follows a pH-dependent hysteresis with a permeation rate that switches by a few orders of magnitude. We establish that this phenomenon is unique to the 1T' phase of MoS2, due to the presence of surface charge and exchangeable ions on the surface. We further demonstrate the potential application of this phenomenon in autonomous wound infection monitoring and pH-dependent nanofiltration. Our work deepens understanding of the mechanism of water transport at the nanoscale and opens an avenue for the development of intelligent membranes.

Vitality, fermentation, aroma profile, and digestive tolerance of the newly selected Lactiplantibacillus plantarum and Lacticaseibacillus paracasei in fermented apple juice

Background

To enrich the probiotic lactic acid bacteria (LAB) strains and expand the commercialization of new fermented juice products, we have identified two LAB strains with excellent potential in fermenting apple juice from pickles.

Methods

The two strains were morphologically, physiologically, and genetically characterized. The strains' fermentation performance and alterations in volatile aroma components of apple juice and ability to survive in a simulated gastrointestinal environment were evaluated.

Results

Two strains were identified as Lacticaseibacillus paracasei (WFC 414) and Lactiplantibacillus plantarum (WFC 502). The growth of WFC 414 and WFC 502 in apple juice for 48 h reached 8.81 and 9.33 log CFU/mL, respectively. Furthermore, 92% and 95% survival rates were achieved in 2 h simulated gastric juice, and 80.7 and 83.6% survival rates in 4 h simulated intestinal juice. During the fermentation, WFC 414 and WFC 502 reduced the soluble sugars and total polyphenols in apple juice, and consumed malic acid to produce large amounts of lactic acid (3.48 and 5.94 mg/mL). In addition, the esters and aldehydes were reduced, and the production of alcohols, acids and ketones was elevated in the apple juice fermented by both strains.

Conclusion

These results show that WFC 414 and WFC 502 have great potential applications in the fermented fruit juice industry.

Screening low-methanol and high-aroma produced yeasts for cider fermentation by transcriptive characterization

The commercial active dry yeast strains used for cider production in China are far behind the requirements of the cider industry development in recent decades. In this study, eight yeasts, including Saccharomyces cerevisiae, Schizosaccharomyces pombe, Pichia bruneiensis, and Pichia kudriavzevii, were screened and assessed by growth performance, methanol production, aroma analysis, and their transcriptive characterization. Saccharomyces cerevisiae strains WFC-SC-071 and WFC-SC-072 were identified as promising alternatives for cider production. Strains WFC-SC-071 and WFC-SC-072 showed an excellent growth capacity characterized by 91.6 and 88.8% sugar utilization, respectively. Methanol production by both strains was below 200 mg/L. Key aroma compounds imparting cider appreciably characteristic aroma increased in cider fermented by strains WFC-SC-071 and WFC-SC-072. RT-qPCR analysis suggested that most genes associated with growth capacity, carbohydrate uptake, and aroma production were upregulated in WFC-SC-071 and WFC-SC-072. Overall, two Saccharomyces cerevisiae strains are the optimal starters for cider production to enable the diversification of cider, satisfy the differences in consumer demand, and promote cider industry development.

Structural modification induced by heat treatments improves the emulsifying attributes of lacquer seed protein isolate

The lacquer seed oil has received extensive attention in the food industry due to its health function, such as regulating blood lipids. But its by-product, lacquer seed meal, is often used as a low-value-added product such as animal feed. Lacquer seed meal contains about 20 % protein, which has amphiphilic properties, and there is limited attention to its emulsifying properties. In this study, the impact of heat treatment on the emulsifying properties of lacquer seed protein isolate (LSPI) was investigated. The EAI and ESI of the 120 °C heated LSPI increased by 77.1 % and 55.2 %, respectively. The emulsions prepared using heat-modified LSPI (120 °C) further showed lower hydroperoxide, TBARS and protein carbonyl contents (only 61.3 %, 61.0 % and 58.6 % of control) after storage. This result indicates that heat-treated LSPI retarded lipid and protein oxidation in LSPI-stabilized emulsions during storage. Changes in protein structure showed that increasing heating temperature resulted in the depolymerization of tertiary structure, higher surface hydrophobicity and lower contents of α-helix of LSPI. These changes in protein structure made the heated LSPIs have better emulsifying properties. Therefore, these findings developed a new use of LSPI and greatly enhanced the potential of LSPI as a natural emulsifier in the food industry.

Ginger (Zingiber officinale) extract mediated green synthesis of silver nanoparticles and evaluation of their antioxidant activity and potential catalytic reduction activities with Direct Blue 15 or Direct Orange 26

The green synthesis of silver nanoparticles (AgNPs) using a water extract of Ginger (Zingiber officinale) root by microwave irradiation and its antibacterial activities have been reported. However, AgNPs prepared from different parts of ginger root water or ethanol extract by ultrasound synthesis and their antioxidant activity and whether the biogenic could be used to catalyze the reduction of hazardous dye are unknown. This study concentrated on the facile green synthesis of AgNPs prepared from different parts (unpeeled ginger, peeled ginger, and ginger peel) of ginger root water or ethanol extract by the ultrasound-assisted method. We studied their antioxidant activity and catalytic degradation of hazardous dye Direct Orange 26 (DO26) and Direct Blue 15 (DB15). The surface plasmon resonance (SPR) peak of AgNPs was at 428-443 nm. The biogenic AgNPs were approximately 2 nm in size with a regular spherical shape identified from TEM analysis. The ethanol extracts of dried unpeeled ginger and peeled ginger, fresh peeled ginger and ginger peel. The Z. officinale AgNPs synthesized by dried unpeeled ginger ethanol extract showed the best antioxidant activity. Their scavenging activities were significantly better than BHT (p <0.05). The different parts of ginger extracts showed no catalytic degradation activities of DB15 and DO26. Still, the synthesized Z. officinale AgNPs exhibited good catalytic degradation activities, while their ability to catalytic degradation to DB15 was better than DO26. In the additive ratio of 3 mL DB15, 0.1 mL NaBH4 and 0.1 mL AgNPs, the degradation rates of DB15 (or DO26) at 15 min, 30 min and 60 min were only 1.8% (0.9%), 2.8% (1.4%) and 3.5% (1.6%) in the absence of AgNPs. When adding Z. officinale AgNPs prepared from dried ginger peel ethanol extract or fresh ginger peel water extract, the degradation rates of DB15 sharply increased to 97% and 93% after 30 min, respectively. In conclusion, ginger extract has good antioxidant properties. Z. officinale AgNPs biosynthesis from ginger extract exhibit excellent catalytic degradation activities, especially for the ginger peel extract. They have application value in the treatment of textile effluents and provide a new idea and method for the comprehensive development and utilization of ginger resources.

Engineering a Feruloyl-Coenzyme A Synthase for Bioconversion of Phenylpropanoid Acids into High-Value Aromatic Aldehydes

Aromatic aldehydes find extensive applications in food, perfume, pharmaceutical, and chemical industries. However, a limited natural enzyme selectivity has become the bottleneck of bioconversion of aromatic aldehydes from natural phenylpropanoid acids. Here, based on the original structure of feruloyl-coenzyme A (CoA) synthetase (FCS) from Streptomyces sp. V-1, we engineered five substrate-binding domains to match specific phenylpropanoid acids. FcsCIA^E407A/K483L, FcsMA^{E407R/I481R/K483R}, FcsHA^{E407K/I481K/K483I}, FcsCA^{E407R/I481R/K483T}, and FcsFA^{E407R/I481K/K483R} showed 9.96-, 10.58-, 4.25-, 6.49-, and 8.71-fold enhanced catalytic efficiency for degrading CoA thioesters of cinnamic acid, 4-methoxycinnamic acid, 4-hydroxycinnamic acid, caffeic acid, and ferulic acid, respectively. Molecular dynamics simulation illustrated that novel substrate-binding domains formed strong interaction forces with substrates' methoxy/hydroxyl group and provided hydrophobic/alkaline catalytic surfaces. Five recombinant E. coli with FCS mutants were constructed with the maximum benzaldehyde, p-anisaldehyde, p-hydroxybenzaldehyde, protocatechualdehyde, and vanillin productivity of 6.2 ± 0.3, 5.1 ± 0.23, 4.1 ± 0.25, 7.1 ± 0.3, and 8.7 ± 0.2 mM/h, respectively. Hence, our study provided novel and efficient enzymes for the bioconversion of phenylpropanoid acids into aromatic aldehydes.

Chlorogenic Acid Ameliorates High-Fat and High-Fructose Diet-Induced Cognitive Impairment via Mediating the Microbiota-Gut-Brain Axis

Chlorogenic acid (CGA) displays cognition-improving properties, but the underlying mechanisms remain unclear. Herein, CGA supplementation (150 mg/kg body weight) for 14 weeks significantly prevented obesity and insulin resistance, cognitive-behavioral disturbances, and synaptic dysfunction induced by a high-fat and high-fructose diet (HFFD). Moreover, CGA supplementation enhanced the expression of genes enriched in the neuroactive ligand-receptor interaction pathway and reduced inflammatory factor expressions. Furthermore, CGA treatment increased gut microbiota diversity and the level of bacterial genera producing SCFAs. CGA also decreased the concentration of energy metabolism substrates, while it increased phosphorylcholine. Finally, we observed a significant correlation among synaptic transmission genes, gut microbiota, and neurotransmission in the CGA supplementation group by targeted multiomics analysis. Together, our results supported that the alteration of gut microbiota and metabolite composition is the underlying mechanism of CGA improving cognitive function. CGA is also a promising intervention strategy to prevent HFFD-induced cognitive impairment.

[Assessment of cognitive function of the elderly by serum metabolites of brain-gut axis]

Objective: To investigate the feasibility of assessing cognitive function of the elderly by serum metabolites of brain-gut axis. Methods: Convenience sampling was used to select 100 and 60 participants from the healthy population cohort and microecological balance cohort of the longevity population in Guangxi, to constitute subset of healthy population and longevity population, respectively. A questionnaire was used to investigate the demographic characteristics of the subjects, 2-5 ml of fasting venous blood was collected from the subjects, and the serum untargeted metabolomics was determined by liquid chromatography tandem mass spectrometry. The biomarkers related to the brain-gut axis were collected through literature retrieval, and the results were intersected with the untargeted metabolites and annotated. Spearman correlation analysis was used to screen serum metabolites of brain-gut axis associated with aging, and multiple linear regression method was used to construct biological age model. The mini mental status examination was used to evaluate the cognitive function of longevity population subsets. The differences of biological age and chronological age of longevity population subsets with different cognitive function were compared. Results: The M (Q₁, Q₃) of subset of healthy population and longevity population were 64 (38, 72) and 97 (95, 99) years old, respectively, and there were 50 (50.0%) and 44 (73.3%) females, respectively. Nine serum metabolites of brain-gut axis were obtained by initial screening, which were propionic acid, glutamic acid, γ-aminobutyric acid (GABA), lactic acid, 5-hydroxytryptamine (5-HT), tryptophan, trimethylamine oxide, dopamine and canine urea. Spearman correlation analysis showed that glutamic acid and dopamine were positively correlated with aging (r values were 0.208 and 0.524, respectively, all P values<0.05), and tryptophan, 5-HT and GABA were negatively correlated with aging (r values were -0.308, -0.533 and -0.213, respectively, all P values<0.05). The biological age model was constructed as: y=49.81-1.18×10^-5× GABA-1.82×10^-4×5-HT+1.99×10^-3×dopamine+1.65×10^-6×glutamic acid -2.04×10^-6×tryptophan+2.36×gender, where y was the biological age (years), the items on the right were the intercept item, the relative concentration of each metabolite, and gender (male=1, female=2). The coefficient of determination of model was 0.50 (P<0.001). The M (Q₁, Q₃) of the chronological age of the subset of longevity population with poor, moderate and good cognitive function were 97 (94, 100), 97 (93, 101) and 96 (94, 101) years old, respectively, and there was no statistical significance in pairwise comparison (all P values>0.05). The M (Q₁, Q₃) of the biological age of the subjects with better cognitive function was 51 (38, 54) years old, which was lower than that of the subjects with poor cognitive function [57 (47, 61)] (P=0.040). Conclusion: The biological age model can be constructed based on serum metabolites of brain-gut axis and used to evaluate the cognitive function of the elderly.

[An epigenetic clock model for assessing the human biological age of healthy aging]

Objective: To construct an epigenetic clock model for assessing and calibrating human biological age. Methods: Convenience sampling was used to select 186 subjects from the longevity cohort of Guangxi Zhuang Antonornous Region from July 1 to November 30, 2019, and 124 subjects from the physical examination population of the Seventh Medical Center of the PLA General Hospital from October 1 to December 31, 2020. Self-designed questionnaire was applied to collect demographic characteristics and family history of disease. Physical examination was applied to determine heart rate and blood pressure. Fasting peripheral venous blood was drawn for determination of fasting plasma glucose, plasma total cholesterol, triglyceride, plasma high-density lipoprotein cholesterol, plasma low-density lipoprotein cholesterol and telomere length. Methylation levels of EDARADD cg09809672, IPO8 cg19722847, NHLRC1 cg22736354, P2RX6 cg05442902 and SCGN cg06493994 were detected by targeted methylation site sequencing. A total of 54 subjects with unqualified quality control of DNA methylation and telomere length were excluded, and 256 subjects' data were finally analyzed. Trend test was used for the change of methylation level among different ages groups, multiple linear regression method was used to build prediction models of biological age. Kendal rank correlation analysis was used to evaluate the correlation of age gap (Gregorian calendar age minus biological age) with telomere length. Independent sample t-test was used to compare the health-related indicators between subjects with different age gap within different age groups. Results: The M(Q₁, Q₃)of age of subjects were 67 (51, 91) years old, including 166 females (64.84%). With increase of age, the methylation levels of gene loci were decreased (EDARADD cg09809672, IPO8 cg19722847 and P2RX6 cg05442902) and increased (NHLRC1 cg22736354 and SCGN cg06493994) (all P values<0.05). The established biological age prediction model was as follows: Y=-53.121×EDARADD cg09809672-137.564×IPO8 cg19722847+141.040×NHLRC1 cg22736354-67.893×P2RX6 cg05442902+149.547×SCGNcg06493994+4.592×sex+64.185 (R²=0.86, P<0.001), where Y was the biological age, and the items in the equation were methylation level, sex (male =1, female =2) and intercept in sequence. The Kendall rank correlation coefficient between age gap and telomere length was 0.731 (P<0.001). Compared with the subjects whose age gaP<0, the subjects with age gaP≥0 had higher systolic blood pressure in adolescence [(88.50±8.89) and (109.83±9.48) mmHg, respectively, 1 mmHg=0.133 kPa]; lower TC [(5.48±0.23) and (3.98±0.54) mmol/L, respectively, ] and TG [(3.51±0.32) and (3.41±0.20) mmol/L] in young adults; lower fasting blood glucose in middle age [(6.17±0.67) and (5.37±0.79) mmol/L, respectively, ] and higher diastolic blood pressure in nonagenarian age [(76.99±6.78) and (83.97±9.36) mmHg, respectively, ] (all P values<0.05). Conclusion: The constructed epigenetic clock model can be used to evaluate and calibrate human biological age.

Dihydromyricetin resists inflammation-induced muscle atrophy via ryanodine receptor-CaMKK-AMPK signal pathway

Skeletal muscle plays a pivotal role in the maintenance of physical and metabolic health. Skeletal muscle atrophy usually results in physical disability, inferior quality of life and higher health care costs. The higher incidence of muscle atrophy in obese and ageing groups is due to increased levels of inflammatory factors during obesity and ageing. Dihydromyricetin, as a bioactive polyphenol, has been used for anti‐inflammatory, anti‐tumour and improving insulin sensitivity. However, there are no published reports demonstrated the dihydromyricetin effect on inflammation‐induced skeletal muscle atrophy. In this study, we first confirmed the role of dihydromyricetin in inflammation‐induced skeletal muscle atrophy in vivo and in vitro. Then, we demonstrated that dihydromyricetin resisted inflammation‐induced skeletal muscle atrophy by activating Ca²⁺‐CaMKK‐AMPK through signal pathway blockers, Ca²⁺ probes and immunofluorescence. Finally, we clarified that dihydromyricetin activated Ca²⁺‐CaMKK‐AMPK signalling pathway through interaction with the ryanodine receptor, its target protein, by drug affinity responsive target stability (DARTS). Our results not only demonstrated that dihydromyricetin resisted inflammation‐induced muscle atrophy via the ryanodine receptor‐CaMKK‐AMPK signal pathway but also discovered that the target protein of dihydromyricetin is the ryanodine receptor. Our results provided experimental data for the development of dihydromyricetin as a functional food and new therapeutic strategies for treating or preventing skeletal muscle atrophy.

Dihydromyricetin Ameliorates Inflammation-Induced Insulin Resistance via Phospholipase C-CaMKK-AMPK Signal Pathway

Patients with metabolic syndrome have a higher risk of type II diabetes and cardiovascular disease. The metabolic syndrome has become an urgent public health problem. Insulin resistance is the common pathophysiological basis of metabolic syndrome. The higher incidence of insulin resistance in obese groups is due to increased levels of inflammatory factors during obesity. Therefore, developing a therapeutic strategy for insulin resistance has great significance for the treatment of the metabolic syndrome. Dihydromyricetin, as a bioactive polyphenol, has been used for anti-inflammatory, antitumor, and improving insulin sensitivity. However, the target of DHM and molecular mechanism of DHM for preventing inflammation-induced insulin resistance is still unclear. In this study, we first confirmed the role of dihydromyricetin in inflammation-induced insulin resistance in vivo and in vitro. Then, we demonstrated that dihydromyricetin resisted inflammation-induced insulin resistance by activating Ca2+-CaMKK-AMPK using signal pathway blockers, Ca2+ probes, and immunofluorescence. Finally, we clarified that dihydromyricetin activated Ca2+-CaMKK-AMPK signaling pathway by interacting with the phospholipase C (PLC), its target protein, using drug affinity responsive target stability (DARTS) assay. Our results not only demonstrated that dihydromyricetin resisted inflammation-induced insulin resistance via the PLC-CaMKK-AMPK signal pathway but also discovered that the target protein of dihydromyricetin is the PLC. Our results provided experimental data for the development of dihydromyricetin as a functional food and new therapeutic strategies for treating or preventing PLC.

[Clinical and imaging features of middle ear hairy polyps]

Objective: To collect the clinical cases of middle ear hairy polyp, and to summarize the imaging features. Methods: We retrospectively analyzed the clinical data of four cases middle ear hairy polyp confirmed by surgical and pathologic between January 2007 and January 2020 at the Affiliated Eye & ENT Hospital of Fudan University. There were three females, one male, with two left ears and two right ears, aged from 1 to 59 years. The CT and MRI imaging of the patients, and the corresponding clinical manifestations were analyzed. Results: Hairy polyps originated from tympanum in one case, originated from Eustachian tube in two cases, exhibiting recurrent otorrhea without evident inducement. The other case, hairy polyps originated from the Eustachian tube pharyngeal orifice and protruded into the nasopharyngeal cavity, with pharynx discomfort and aural fullness, endoscope showed offwhite polypoid mass with a little hair. All the four cases presented polypoid soft tissue masses on CT and MRI imaging, containing soft tissue wall and a large amount of adipose tissue, with soft tissue in the center of the mass which liked the core, and enhanced. MRI showed stratified arrangement of fat and soft tissue in the wall of the mass. Four cases all had surgical treatment, postoperative pathology examination presented that hair follicles, mature sebaceous glands and other skin appendages were found under squamous epithelium. A large amount of adipose tissue, part of muscle tissue, cartilage tissue, and some fibro-collagenous tissue were proliferated in the mass, accompanied by collagen degeneration. Conclusion: The middle ear hairy polyps has imaging characteristics, the polypoid soft tissue mass usually looks smooth and contains a large amount of adipose tissue, with a soft tissue in the center, and can be suggestively diagnosed by CT and MRI.

LncRNAs as Therapeutic Targets and Potential Biomarkers for Lipid-Related Diseases

Lipid metabolism is an essential biological process involved in nutrient adjustment, hormone regulation, and lipid homeostasis. An irregular lifestyle and long-term nutrient overload can cause lipid-related diseases, including atherosclerosis, myocardial infarction (MI), obesity, and fatty liver diseases. Thus, novel tools for efficient diagnosis and treatment of dysfunctional lipid metabolism are urgently required. Furthermore, it is known that lncRNAs based regulation like sponging microRNAs (miRNAs) or serving as a reservoir for microRNAs play an essential role in the progression of lipid-related diseases. Accordingly, a better understanding of the regulatory roles of lncRNAs in lipid-related diseases would provide the basis for identifying potential biomarkers and therapeutic targets for lipid-related diseases. This review highlighted the latest advances on the potential biomarkers of lncRNAs in lipid-related diseases and summarised current knowledge on dysregulated lncRNAs and their potential molecular mechanisms. We have also provided novel insights into the underlying mechanisms of lncRNAs which might serve as potential biomarkers and therapeutic targets for lipid-related diseases. The information presented here may be useful for designing future studies and advancing investigations of lncRNAs as biomarkers for diagnosis, prognosis, and therapy of lipid-related diseases.

Dihydromyricetin Imbues Antiadipogenic Effects on 3T3-L1 Cells via Direct Interactions with 78-kDa Glucose-Regulated Protein

BACKGROUND

Obesity is among the most serious public health problems worldwide, with few safe pharmaceutical interventions. Natural products have become an important source of potential anti-obesity therapeutics. Dihydromyricetin (DHM) exerts antidiabetic effects. The biochemical target of DHM, however, has been unknown. It is crucial to identify the biochemical target of DHM for elucidating its physiological function and therapeutic value.

OBJECTIVES

The objective of this study was to identify the biochemical target of DHM.

METHODS

An abundant antiadipogenic flavanonol was extracted from the herbal plant Ampelopsis grossedentata through bioassay-guided fractionation and characterized with high-resolution LC-MS and 1H and 13C nuclear magnetic resonance. Antiadipogenic experiments were done with mouse 3T3-L1 preadipocytes. A biochemical target of the chemical of interest was identified with drug affinity responsive target stability assay. Direct interactions between the chemical of interest and the protein target in vitro were predicted with molecular docking and subsequently confirmed with surface plasmon resonance. Expression levels of peroxisome proliferator-activated receptor γ (PPARγ), which is associated with 78-kDa glucose-regulated protein (GRP78), were measured with real-time qPCR.

RESULTS

DHM was isolated, purified, and structurally characterized. Cellular studies showed that DHM notably reduced intracellular oil droplet formation in 3T3-L1 cells with a median effective concentration of 294 μM (i.e., 94 μg/mL). DHM targeted the ATP binding site of GRP78, which is associated with adipogenesis. An equilibrium dissociation constant between DHM and GRP78 was 21.8 μM. In 3T3-L1 cells upon treatment with DHM at 50 μM (i.e., 16 μg/mL), the expression level of PPARγ was downregulated to 53.9% of the solvent vehicle control's level.

CONCLUSIONS

DHM targets GRP78 in vitro. DHM is able to reduce lipid droplet formation in 3T3-L1 cells through a mode of action that is plausibly associated with direct interactions between GRP78 and DHM, which is a step forward in determining potential applications of DHM as an anti-obesity agent.

Potential Therapeutic Targeting of lncRNAs in Cholesterol Homeostasis

Maintaining cholesterol homeostasis is essential for normal cellular and systemic functions. Long non-coding RNAs (lncRNAs) represent a mechanism to fine-tune numerous biological processes by controlling gene expression. LncRNAs have emerged as important regulators in cholesterol homeostasis. Dysregulation of lncRNAs expression is associated with lipid-related diseases, suggesting that manipulating the lncRNAs expression could be a promising therapeutic approach to ameliorate liver disease progression and cardiovascular disease (CVD). However, given the high-abundant lncRNAs and the poor genetic conservation between species, much work is required to elucidate the specific role of lncRNAs in regulating cholesterol homeostasis. In this review, we highlighted the latest advances in the pivotal role and mechanism of lncRNAs in regulating cholesterol homeostasis. These findings provide novel insights into the underlying mechanisms of lncRNAs in lipid-related diseases and may offer potential therapeutic targets for treating lipid-related diseases.

Elevated β-Carotene Production Using Codon-Adapted CarRA&B and Metabolic Balance in Engineered Yarrowia lipolytica

β-carotene is a precursor of vitamin A and has multiple physiological functions. Producing β-carotene by microbial fermentation has attracted much attention to consumers' preference for natural products. This study focused on improving β-carotene production by constructing codon-adapted genes and minimizing intermediate accumulation. The codon-adapted CarRA and CarB genes from the industrial strain of Blakeslea trispora were integrated into the genome of the Yarrowia lipolytica to construct YL-C0, the baseline strain for producing β-carotene. Thereafter, the β-carotene biosynthetic pathway's metabolic balance was accurately regulated to reduce the intermediates' accumulation. Notably, the β-carotene content increased by 21 times to reach 12.5 dry cell weight (DCW) mg/g when minimizing HMG-CoA and FPP accumulation. Further, we improved the expression levels of the CarRA and CarB genes to minimize the accumulation of phytoene and lycopene. Total production of β-carotene of 1.7 g/L and 21.6 mg/g DCW was achieved. These results reveal that the rate-limiting enzymes CarRA and CarB of B. trispora exhibited higher catalytic activity than the same enzymes from other microorganisms. Promoting metabolic balance by minimizing the accumulation of intermediates is a very effective strategy for increasing β-carotene. The β-carotene-producing strain constructed in this study has established the foundation for its potential use in industrial production. These successful engineering strategies also provide a foundation for large-scale production of other terpenoids.

The synergistic effect of grain boundary and grain orientation on micro-mechanical properties of austenitic stainless steel

Micro/nano-scale deformation behavior including hardness, elastic modulus, and pop-ins, was studied in a medical austenitic stainless steel followed by post-mortem EBSD characterization. Relatively higher hardness and modulus was observed near {101} and more pop-ins occurred in this orientation at high loading rate. The activation volume (v) obtained from nanoindentation had weak dependence on grain orientation and was ~10-20 b³, indicating that neither diffusional creep processes nor conventional dislocation segments passing through dislocation forests controls plastic deformation in our study. The plastic zone radius (c) and the distance of the indent from the grain boundary (d) were used to describe the effect of grain boundary on the pop-in effect. The ratio of c/d meets amplitude version of Gaussian peak function distribution for a given orientation, whose peak value remains nearly constant for all the orientations.

[Analysis of distribution characteristics and influencing factors of healthy and long-lived people in Shanglin area of Nanning, Guangxi Zhuang Autonomous Region]

Objective: To explore the epidemiologic characteristics of long-lived population and influencing factors in Shanglin county of Guangxi and provide scientific basis for the study of health and longevity in Guangxi. Methods: We collected and analyzed the general demographic cross-sectional data of the long-lived individuals (≥90 years old) in 11 villages and towns by multi-source registration and face-to-face interview. The age group control design was adopted to conduct a comparison among the longevity group (90-100 years old), centenarian group (≥100 years old), the longevity plus centenarian group and control group (local population aged 40-85 years), and identify the factors related to longevity. Results: Among the 496 007 people registered in Shanglin, 1 533 were aged ≥90 years, including 1 453 in the longevity group, with an average age of (92.84±2.46) years, and 80 in the centenarian group, with an average age of (102.67±2.60) years. The spatial distribution of long-lived individuals and centenarians was mainly in the north and central areas, and sparse in southwest area. Analysis on factors related to health and longevity indicated that old people with Zhuang ethnic (OR=1.551,95%CI:1.308-1.838), married (OR=55.507,95%CI:36.087-85.377) and moderately high waist-to-hip ratio (OR=258.056,95%CI:27.775-2 397.569), and SBP (OR=1.019,95%CI:1.013-1.026) tended to live longer. Conclusions: We found that the rate of longevity in Shanglin was higher than the average level in Guangxi and China. Longevity in Shanglin country had unique spatial and population distribution characterics of female longevity more than male longevity, mainly Zhuang ethnic and so on. Being women, married, family history of longevity, appropriate high waist-to-hip ratio, SBP and blood sugar level might be positive factors for longevity in Shanglin, but the impacts of other factors on longevity need further study.

[The study on the distribution characteristics and relevant factors of healthy and long-lived people in multiple regions of Guangxi Zhuang Autonomous Region]

Objective: To investigate the epidemiological characteristics and relevant factors among individuals characterized by their longevity in multiple regions of Guangxi Zhuang Autonomous Region, and provide a valuable scientific perspective for the research in health and longevity of the elderly in Guangxi. Methods: Registration and face-to-face questionnaire on a door-to-door basis were adopted to collect the demographic characteristics of the long-lived individuals (≥90 years old) in Bama of Hechi city, Yongfu of Guilin city, Dongxing of Fangchenggang city, Guangxi. Then, among the local general population, individuals within the age group between 40 and 85 years old were selected randomly as controls. Correlations were then analyzed between the relative health and longevity of the subjects and their gender, ethnicity, family history, disease history, marital status, the number of family generations, the number of children, smoking, drinking, outdoor activities, sleep and other health-related factors, then the result was subject to further analysis by comparing the long-lived population and the control population respectively. Results: Among 691 500 of the permanent residents of Bama, Yongfu and Dongxing city, 1 005 cases were 90 years old and over with a ratio of 145.34 out of 100 000 persons; within the 1 005 cases, 944 were aged between 90 and 100 (longevity rate: 136.51/100 000) with an average age of (93.28±2.57); 61 cases were aged 100 or over, arriving at a centenarian rate of 8.82/100 000 with an average age of (102.00±3.05) years. Significant differences were found just among three particular factors - regional distribution (P=0.014), history of disease (P=0.002), four generations of family (P=0.008) between nonagenarians and centenarians (P<0.05), while the other 15 indicators did not show anything noteworthy. The result indicated that longevity and centenarians might be the same group and then we combined both groups into one. By cross-comparison between the longevity-plus- centenarians and the control group in the region, factors listed below exhibited significant correlation with health and longevity: marital status (OR=26.469, 95%CI: 13.208-53.045), number of generations within the family (OR=5.419, 95%CI: 3.418-8.592), number of male offspring (OR=2.013, 95%CI: 1.555-2.607), number of female offspring (OR=1.380, 95%CI: 1.122-1.696), and the frequency of outdoor activities (OR=10.226, 95%CI: 3.164-33.045). Conclusions: The longevity rate is higher in the general natural population in Bama, Yongfu and Dongxing of Guangxi. The phenomenon may owe to favorable family structure, atmosphere within or out of the family or other elements related with social surrounding. Among them all, mentality, inclination to physical exercise and regular rhythm of life may all exert tremendous contributory influence here.

Anthocyanins Are Converted into Anthocyanidins and Phenolic Acids and Effectively Absorbed in the Jejunum and Ileum

Anthocyanins have been known for their health benefits. However, the in vivo digestion and absorption of anthocyanins through the gastrointestinal tract have not been fully clarified, creating challenges for understanding why anthocyanins have high biological activities and purported low bioavailability in vivo. Twenty-seven male rats were intubated with a 500 mg/kg dose of cyanidin-3-glucoside (C3G). Samples from rats' stomach, duodenum, jejunum, ileum, colon, and serum were collected at 0.5, 1, 2, 3, 4, 5, 6, 12, and 24 h after intubation. Three rats without C3G were used as the control with samples collected at 0 h. C3G and its metabolites in each sample were analyzed using high-performance liquid chromatography-PDA-electrospray ionization-MS/MS. These in vivo studies' results unequivocally demonstrated that cyanidin and phenolic acids were the primary C3G metabolites absorbed, mainly in the jejunum and ileum, between 1 and 5 h post-ingestion. We speculate that C3G uses phloroglucinaldehyde and protocatechuic acid metabolic pathways in its metabolism in vivo.

Dissolved-oxygen feedback control fermentation for enhancing β-carotene in engineered Yarrowia lipolytica

The DO-stat fed-batch fermentation was carried out to explore the volumetric productivity of β-carotene in engineered Yarrowia lipolytica C11 strain. Using DO-stat fed-batch fermentation, we achieved 94 g/L biomass and 2.01 g/L β-carotene. Both biomass and β-carotene were about 1.28-fold higher than that in fed-batch fermentation. The ATP, NADP+/NADPH, and gene expression levels of tHMG, GGS1, carRA, and carB were promoted as compared to that in fed-batch fermentation. As for as the kinetic parameters in DO-stat fed-batch fermentation, μm', Yx/s', and Yp/s' was 0.527, 0.353, and 0.158, respectively. The μm' was elevated 4.66-fold than that in fed-batch fermentation. These data illustrate that more dissolved oxygen increased the biomass. The Yx/s' and Yp/s' were increased 1.15 and 22.57-fold, which suggest that the DO-stat fed-batch fermentation reduced the Crabtree effect and improved the utilization rate of glucose. Therefore, DO-stat fed-batch fermentation is a promising strategy in the industrialized production of β-carotene.

MiR-92b-3p inhibits proliferation and migration of C2C12 cells

Skeletal muscle, a critical component of the mammalian body, is essential for normal body movement. miRNAs are well documented in gene post-transcription regulation in many biological processes, including muscle development and maintenance. miR-92b-3p, which is often associated with tumorigenesis, has never been explored in myoblast development. Here, we used murine-derived C2C12 myoblasts to explore the potential functions of miR-92b-3p in skeletal muscle development. Our results demonstrated that miR-92b-3p mimics inhibited C2C12 cell proliferation and migration, whereas miR-92b-3p inhibitor promoted C2C12 cell proliferation and migration. C2C12 cell differentiation was not affected by miR-92b-3p mimics, according to immunofluorescence and qPCR results. Serum- and glucocorticoid-induced kinase 3 (SGK3) was predicted and validated as a target of miR-92b-3p. Overexpression of SGK3 promoted C2C12 cell proliferation. SGK3 and miR-92b-3p formed a regulatory pathway to modulate C2C12 cell proliferation. In conclusion, miR-92b-3p inhibited C2C12 cell proliferation by targeting SGK3 and impeded C2C12 cell migration.

FAM83H and Autosomal Dominant Hypocalcified Amelogenesis Imperfecta

Autosomal dominant hypocalcified amelogenesis imperfecta (ADHCAI; OMIM #130900) is a genetic disorder exhibiting severe hardness defects and reduced fracture toughness of dental enamel. While the condition is nonsyndromic, it can be associated with other craniofacial anomalies, such as malocclusions and delayed or failed tooth eruption. Truncation mutations in FAM83H (OMIM *611927) are hitherto the sole cause of ADHCAI. With human genetic studies, Fam83h knockout and mutation-knock-in mouse models indicated that FAM83H does not serve a critical physiologic function during enamel formation and suggested a neomorphic mutation mechanism causing ADHCAI. The function of FAM83H remains obscure. FAM83H has been shown to interact with various isoforms of casein kinase 1 (CK1) and keratins and to mediate organization of keratin cytoskeletons and desmosomes. By considering FAM83H a scaffold protein to anchor CK1s, further molecular characterization of the protein could gain insight into its functions. In this study, we characterized 9 kindreds with ADHCAI and identified 3 novel FAM83H truncation mutations: p.His437*, p.Gln459*, and p.Glu610*. Some affected individuals exhibited hypoplastic phenotypes, in addition to the characteristic hypocalcification enamel defects, which have never been well documented. Failed eruption of canines or second molars in affected persons was observed in 4 of the families. The p.Glu610* mutation was located in a gap area (amino acids 470 to 625) within the zone of previously reported pathogenic variants (amino acids 287 to 694). In vitro pull-down studies with overexpressed FAM83H proteins in HEK293 cells demonstrated an interaction between FAM83H and SEC16A, a protein component of the COP II complex at endoplasmic reticulum exit sites. The interaction was mediated by the middle part (amino acids 287 to 657) of mouse FAM83H protein. Results of this study significantly extended the phenotypic and genotypic spectrums of FAM83H-associated ADHCAI and suggested a role for FAM83H in endoplasmic reticulum-to-Golgi vesicle trafficking and protein secretion (dbGaP phs001491.v1.p1).

Promoting the Synthesis of Precursor Substances by Overexpressing Hexokinase (Hxk) and Hydroxymethylglutaryl-CoA Synthase (Erg13) to Elevate β-Carotene Production in Engineered Yarrowia lipolytica

As a valuable carotenoid, β-carotene is commercially used in food, cosmetics, animal feeds, and other industries. Metabolic engineering of microorganisms has been widely explored to improve the production of β-carotene. Compared with the traditional genetic modifications mainly focused on the pathways of mevalonate (MVA) and β-carotene biosynthesis, this study aims to increase the β-carotene production through promoting the synthesis of precursor substances by overexpressing hexokinase and hydroxymethylglutaryl-CoA synthase in an engineered Yarrowia lipolytica. In this study, we investigated the effect of the unique hexokinase gene (Hxk) overexpression on β-carotene accumulation and glucose consumption. The Hxk gene was introduced into a β-carotene producing strain Y.L-1 to generate strain Y.L-2, and this increased the β-carotene content by 98%. Overexpression of the Hxk gene led to increasing in hexokinase activity (329% higher), glucose-6-phosphate content (92% higher), and improvement of the transcriptional level of Hxk (315% higher) compared to the control Y.L-1 strain. Moreover, Hxk overexpression accelerated the utilization rate of glucose. The gene erg13 encoding hydroxymethylglutaryl-CoA synthase was also overexpressed to increase the precursor supply for β-carotene biosynthesis. Recombinant Y.L-4 harboring two copies of erg13 produced 8.41 mg/g dry cell weight (DCW) of β-carotene, which was 259% higher than Y.L-1. The β-carotene content of 9.56 mg/g DCW was achieved in strain Y.L-6 by integrating erg13 into the chromosome and Hxk overexpression. The 3-Hydroxy-3-Methylglutaryl-CoA content in the cells was increased by overexpressing two copies of the erg13 gene. Finally, the titer of β-carotene reached 2.4 g/L using a 50 L bioreactor by the engineered strain, and the fermentation cycle was shortened from 144 to 120 h. Overall, overexpression of Hxk and erg13 could improve β-carotene production and successfully overcoming the bottleneck of precursor generation to support a more efficient pathway for the production of the target product. Our results revealed a novel strategy to engineer the pathway of β-carotene synthesis.

Cyanidin-3-glucoside from Black Rice Ameliorates Diabetic Nephropathy via Reducing Blood Glucose, Suppressing Oxidative Stress and Inflammation, and Regulating Transforming Growth Factor β1/Smad Expression

Diabetic nephropathy (DN) is one of the serious complications in diabetes. Cyanidin-3-glucoside (C3G) from black rice was reported to have hypoglycemic effects and an anti-osteoporosis effect in diabetic rats. Whether it has preventive effects on DN has not been reported. In this study, we established a rat model of DN, and C3G at two doses (10 and 20 mg kg^-1 day^-1) were administered to see its anti-DN effect. A total of 8 weeks of C3G supplementation decreased blood glucose and serum insulin, improved the renal function, and relieved renal glomerular sclerosis and interstitial fibrosis of DN rats. Also, the kidneys of DN rats had improved the oxidative defense system. Pro-inflammatory mediators were markedly reduced in serum and kidneys of the C3G-treated groups. Transforming growth factor β1 (TGF-β1), phosphor-Smad2, and phosphor-Smad3 protein expression levels were significantly decreased in the kidney of the C3G-treated group, whereas the Smad7 expression level was upregulated by C3G. Our results indicate that C3G can ameliorate DN via antioxidative stress and anti-inflammation and regulate the TGF-β1/Smad2/3 pathway. Our results suggest that C3G from black rice might be used as a renal-protective nutrient in DN.

Overexpression of △12, △15-Desaturases for Enhanced Lipids Synthesis in Yarrowia lipolytica

Microbial oil triacylglycerol (TAG) from the renewable feedstock attract much attention. The oleaginous yeast Yarrowia lipolytica has become the most studied for lipid biosynthesis. Fatty acid desaturases catalyze the introduction of a double bond into fatty-acid hydrocarbon chains to produce unsaturated fatty acids. Desaturases are known to enhance lipid accumulation. In this study, we have achieved a significant increase in lipid production and increase the unsaturated fatty acids content in Y. lipolytica. By comparing the expression of the native genes of △-9 stearoyl-CoA desaturase (SCD) and △12 desaturase (△12D), and an exogenous △15 desaturase (△15D) from flax in the strain with deleted peroxisomal biogenesis factor 10 (PEX10) and overexpressed diacylglyceride acyl-transferase (DGA1), we found that the strain with overexpressed △15 desaturase accumulated 30.7% lipid. Simultaneously, we explored the effect of two copies of desaturase genes (12D-SCD, 15D-SCD, 12D-15D) on lipid production, and found co-expression of △12D and △15D accumulated 42.6% lipid. The lipid content was further increased by 56.3% through the deletion of the multifunctional enzyme (MFE1) and the overexpression of acetyl-CoA carboxylase (ACC1). Finally, the lipid productivity of 50 g/L and maximal lipid content of 77.8% DCW are obtained using a 5-L stirred-tank bioreactor during the stationary phase in the engineered YL-10. Our result demonstrated that the △12 and △15 desaturases play an important role in lipid production in Y. lipolytica and provides an effective strategy for biodiesel development.

Accuracy of genomic prediction using mixed low-density marker panels

Low-density single-nucleotide polymorphism (LD-SNP) panel is one effective way to reduce the cost of genomic selection in animal breeding. The present study proposes a new type of LD-SNP panel called mixed low-density (MLD) panel, which considers SNPs with a substantial effect estimated by Bayes method B (BayesB) from many traits and evenly spaced distribution simultaneously. Simulated and real data were used to compare the imputation accuracy and genomic-selection accuracy of two types of LD-SNP panels. The result of genotyping imputation for simulated data showed that the number of quantitative trait loci (QTL) had limited influence on the imputation accuracy only for MLD panels. Evenly spaced (ELD) panel was not affected by QTL. For real data, ELD performed slightly better than did MLD when panel contained 500 and 1000 SNP. However, this advantage vanished quickly as the density increased. The result of genomic selection for simulated data using BayesB showed that MLD performed much better than did ELD when QTL was 100. For real data, MLD also outperformed ELD in growth and carcass traits when using BayesB. In conclusion, the MLD strategy is superior to ELD in genomic selection under most situations.

Elevated β-Carotene Synthesis by the Engineered Rhodobacter sphaeroides with Enhanced CrtY Expression

β-Carotene is a precursor of vitamin A and a dietary supplement for its antioxidant property. Producing β-carotene by microbial fermentation has attracted much attention owing to consumers' preference for the natural product. In this study, an engineered photosynthetic Rhodobacter sphaeroides producing β-carotene was constructed by the following strategies: (1) five promoters of different strengths were used to investigate the effect of the expression level of crtY on β-carotene content. It was found that P_rrnB increased the β-carotene content by 109%. (2) blocking of the branched pentose phosphate pathway by zwf deletion, and (3) overexpressing dxs could restore the transcriptional levels of crtE and crtB. Finally, the engineered RS-C3 has the highest β-carotene content of 14.93 mg/g dry cell weight (DCW) among all of the reported photosynthetic bacteria and the β-carotene content reached 3.34 mg/g DCW under light conditions. Our results will be available for industrial use to supply a large quantity of natural β-carotene.

Anthocyanin-rich extract from black rice (Oryza sativa L. Japonica) ameliorates diabetic osteoporosis in rats

Diabetic osteoporosis (DOP) is a systemic endocrine-metabolic osteopathy which has the characteristics of bone mineral density (BMD) reduction and bone microstructural destruction. Although anthocyanin-rich extract from black rice (AEBR) was reported to have a beneficial effect on diabetic rats, no studies have been performed on whether black rice anthocyanins are beneficial for diabetic osteoporosis. Therefore, in this study, a streptozotocin-induced diabetic rat model was established to investigate the protective effect of AEBR on diabetes-induced osteoporosis and its possible mechanism. AEBR at three doses (0.5, 1.0, and 2.0 g kg^-1 d^-1) were administered by oral gavage to diabetic rats for 8 weeks. The blood glucose, BMD, bone histomorphometry parameters, serum bone turnover biomarkers, bone marrow adipocyte numbers, as well as osteoprotegerin (OPG), runt-related transcription factor 2 (RUNX 2), and receptor activator of nuclear factor-κ B ligand (RANKL) protein expression in bone and serum were detected. The results indicated that AEBR dose-dependently decreased the blood glucose, increased the BMD, and decreased the serum bone turnover markers. The bone microstructure and osteoclast numbers in bone tissues returned to normal in the high AEBR dosage group; at the same time, the AEBR dose-dependently suppressed bone marrow adipogenesis. The RUNX 2 as well as the OPG/RANKL ratio in diabetic rats' bone tissues increased significantly in the AEBR treatment group. Our results indicate that AEBR administration can ameliorate bone loss caused by diabetes; this is mainly attributed to its inhibition of bone turnover, suppression of bone marrow adipogenesis, and up-regulation of RUNX 2 and the OPG/RANKL expression ratio.

MiR-501-3p Forms a Feedback Loop with FOS, MDFI, and MyoD to Regulate C2C12 Myogenesis

Skeletal muscle plays an essential role in maintaining body energy homeostasis and body flexibility. Loss of muscle mass leads to slower wound healing and recovery from illness, physical disability, poor quality of life, and higher health care costs. So, it is critical for us to understand the mechanism of skeletal muscle myogenic differentiation for maintaining optimal health throughout life. miR-501-3p is a novel muscle-specific miRNA, and its regulation mechanism on myoblast myogenic differentiation is still not clear. We demonstrated that FOS was a direct target gene of miR-501-3p, and MyoD regulated miR-501-3p host gene Clcn5 through bioinformatics prediction. Our previous laboratory experiment found that MDFI overexpression promoted C2C12 myogenic differentiation and MyoD expression. The database also showed there is an FOS binding site in the MDFI promoter region. Therefore, we hypothesize that miR-501-3p formed a feedback loop with FOS, MDFI, and MyoD to regulate myoblast differentiation. To validate our hypothesis, we demonstrated miR-501-3p function in the proliferation and differentiation period of C2C12 cells by transfecting cells with miR-501-3p mimic and inhibitor. Then, we confirmed there is a direct regulatory relationship between miR-501-3p and FOS, MyoD and miR-501-3p, FOS and MDFI through QPCR, dual-luciferase reporter system, and ChIP experiments. Our results not only expand our understanding of the muscle myogenic development mechanism in which miRNA and genes participate in controlling skeletal muscle development, but also provide treatment strategies for skeletal muscle or metabolic-related diseases in the future.

[Correlation between breast density and age, breast cancer molecular subtype]

Objective: To explore the correlation between breast density and breast cancer molecular subtype. Methods: The data of 1 407 cases of breast cancer immunohistochemistry and preoperative mammography in Tianjin Medical University Cancer Institute and Hospital from August 2015 to August 2016 were retrospectively analyzed. All cases were divided into four groups: <45 years old, 45-54 years old, 55-64 years old and ≥ 65 years old, and all groups were divided into four molecular subtypes: Luminal A, Luminal B, HER2-enriched and triple-negative according to immunohistochemical results. Person correlation test was used to analyze the correlation between breast density and age; Kruskal-Wallis test was used to analyze the difference in breast density between different molecular subtypes. Results: There was a negative correlation between breast density and age (r=-0.55, P<0.01). Descriptive analysis results showed that the mean breast density of<45 years old, 45-54 years old, 55-64 years old and ≥65 years old was 20.0%±7.3%, 16.2%±8.4%, 10.5%±5.2%, and 7.9%±3.2%, respectively. The mean breast density of Luminal A, Luminal B, HER2-enriched and triple-negative was 14.0%±8.1%, 14.5%±7.6%, 14.8%±7.7% and 13.2%±7.3%, respectively. Kruskal-Wallis test showed significant statistical differences in breast density among molecular subtypes in the group of<45 years old (P<0.05), while no statistical significance in other groups (all P>0.05). Conclusion: There is correlation between breast density and breast cancer molecular subtype in young patients, but whether breast density has a potential evaluation effect on breast cancer molecular subtype still needs to be further studied.

Limb-salvage treatment of malignant tumors of the limbs

The aim of this study was to explore the clinical efficacy of limb-salvage therapy for malignant bone tumors of the limbs using two surgical methods. This investigation presents a retrospective study of malignant bone tumors of the limbs in 42 patients. Participants were divided into two groups: group A of 25 patients who were treated with artificial prosthesis replacement, and group B of 17 patients treated with bone inactivation. By collection of clinical data, the survival rate, surgical complications, quality of life, pain relief and postoperative limb function following artificial prosthesis replacement and tumor inactivation were comprehensively evaluated in patients with malignant bone tumors of the limbs. Group A had significantly higher Karnofsky quality of life scores compared to group B after six months (P=0.027). The Enneking scores of limb functions in group A were significantly higher than those of group B (P=0.022). In group A the postoperative limb function score was good and excellent in 92% and in group B in 64.7%. There were significantly more postoperative complications in group B compared with group A (P=0.027), but no significant difference in the recurrence rate in the two group (P=0.976). The study results can provide reference for surgical treatment of the patients with malignant bone tumors.

Effect of branched chain amino acids on perioperative temperature, glucose level and fat metabolism in patients with gastrointestinal tumors

This study aimed to investigate the effect of branched chain amino acids (BCCAs) on perioperative temperature, glucose and fat metabolism in patients with gastrointestinal tumors. Fifty-six patients undergoing gastrointestinal tumor surgery were included in the study and randomly divided into two groups of 28 patients each: an experimental and a control group. During surgery, the experimental group received 5.64mL·Kg-1·h-1(4KJ·Kg-1·h-1) of BCCAs intravenously, through an infusion pump, and the control group received an equal volume of NaCl 0.9%. Vital signs were continuously monitored during the operation. Nasopharynx temperature levels of glucose, insulin, free fatty acid and ketone bodies in the blood were determined 30 min before anesthesia (t 0), after anesthesia and before surgery (t 1), 30 min after the start of surgery (t 2), 2 h after start of surgery (t 3) and 1 h after the end of surgery (T4). Patients’ shivering intensity (Wrench grading) and pain degree [Visual analogue scale (VAS)]) were estimated 1 h after the endotracheal tube was removed. Nasopharynx temperature was decreased (p less than 0.05) in both groups after anesthesia induction, while 1 h after the tube was removed it was higher in the experimental group than the control group (p less than 0.05); compared with pre-surgery values, blood glucose levels were increased during surgery in both groups, but the experimental group had a lower increasing trend compared to the control group, though without statistical significance (p>0.05). Insulin levels were significantly different between the two groups at all time-points during surgery (p less than 0.05). However, the rising trend of the experimental group was more dramatic during the period from t 0 to t 3. One hour after surgery (t 4), the insulin levels varied, but still at higher levels than pre-surgery, with a significant difference (p less than 0.05); levels of free fatty acids had a downward trend in both groups, and levels in the experimental group continued to decline until 1 h after surgery. Patients who received branched chain amino acids had less temperature decrease during surgery. Moreover, blood glucose levels were not increased, which limits fat mobilization and leads to production of ketone bodies, reduces the shivering and its intensity after surgery.

Interleukin-2 reverses CD8(+) T cell exhaustion in clinical malignant pleural effusion of lung cancer

Malignant pleural effusion (MPE) is a poor prognostic sign for cancer patients, whereas the functional condition of MPE CD8(+) T cells is unknown. Intracavitary immunotherapy with interleukin (IL)-2 has been proven effective in controlling MPE. To elucidate the underlying mechanism, 35 lung cancer (LC) patients with MPE and 12 healthy donors were included in this study. For the IL-2 therapy experiments, after draining partial MPE, we treated 14 patients by administrating IL-2 (3 or 5 × 10(6) U in 50 ml saline) into the thoracic cavity. Before and after IL-2 treatment (40-48 h), the MPE and peripheral blood (PB) were obtained from the subjects. PB from healthy volunteers was collected as control. The expression of programmed cell death 1 (PD-1), granzyme B (GzmB), interferon (IFN)-γ and the proliferation were analysed in CD8(+) T cells from MPE and PB. The CD8(+) T cells in the MPE of LC patients showed lowest GzmB, IFN-γ and proliferation but highest PD-1 expression, compared with that in PB of LC patients and healthy donors. IL-2 treatment reduced the expression of PD-1, increased the expression of GzmB and IFN-γ and enhanced the proliferation of CD8(+) T cells in MPE. In addition, IL-2 treatment reduced carcino-embryonic antigen (CEA) level in MPE. These results indicate that MPE CD8(+) T cells exhibit exhaustion phenotype which can be reversed by IL-2 therapy.

Development of primer pairs from diverse chloroplast genomes for use in plant phylogenetic research

Variation in the chloroplast DNA sequence is useful for plant phylogenetic studies. However, the number of variable sequences provided by chloroplast DNA for suggested genes or genomic regions in plant phylogenetic analyses is often inadequate. To identify conserved regions that can be used to design primers and amplify variable sequences for use in plant phylogenetic studies, the complete chloroplast genomic sequences of six plant species (including Oryza sativa, Arabidopsis thaliana, Glycine max, Lotus japonicus, Medicago truncatula, and Phaseolus vulgaris), searched from the taxonomy database of NCBI were investigated. A total of 93 conserved regions, 32 in large single copy and 61 in inverted repeat regions, were identified. A set of five primer pairs were designed according to the conserved sequences located in the psbA~trnK, psbB~psbH, rpl23~trnI, trnR~trnN, and trnY~trnD regions to amplify variable DNA fragments. An additional 18 plant accessions from 14 species were used to validate their utility. Each of the tested species could be distinguished by length polymorphisms of fragments amplified with the five primer pairs. trnR~trnN and rpl23~trnI amplified fragments specific to monocot and legume species, respectively. Three primer pairs located in the psbA~trnK, psbB~psbH, and trnR~trnN regions were applied to amplify variable DNA sequences for phylogenetic analysis using the maximum parsimony method. The consistent result between taxonomy and phylogenetic analysis on the variable sequences amplified with these three primer pairs was revealed. The five newly developed primer pairs are recommended as tools for use in the identification of plant species and in phylogenetic studies.

Genetic diversity among red swamp crayfish (Procambarus clarkii) populations in the middle and lower reaches of the Yangtze River based on AFLP markers

The red swamp crayfish has become one of the most important freshwater aquaculture species in China. At present, although it is widely distributed in the middle and lower reaches of the Yangze River basin, little is known about its population genetics and geographic distribution in China. We estimated the genetic diversity among 6 crayfish populations from 4 lakes (Hongze Lake, Poyang Lake, Dongting Lake, and Yue Lake) using AFLPs. A total of 129 loci were generated with 5 EcoRI-MseI primer combinations and scored as binary data in 139 individuals. These data were analyzed by cluster methods with the NTSYSpc software package. The 6 populations were separated into 3 major clusters by principal coordinate analysis and cluster analysis. Among the 6 populations, the highest gene diversity was found within the Nanjing population. Analysis of molecular variance demonstrated that most variation occurred within populations (91.20%). The estimated average GST value across all loci was 0.4186, suggesting (very) low gene flow among the different localities. We conclude that there is high genetic differentiation among crayfish in the middle and lower reaches of the Yangze River. This information will help in the selection of high-quality individuals for artificial reproduction.

Removal of methylene blue from water by gamma-MnO2

Methylene blue (MB) is a cationic dyestuff, which is particularly resistant to biodegradation. The molecular sieved gamma-MnO2 was used as an adsorbent/oxidant to remove the MB at room temperature and in visible light. The removal efficiency was mainly evaluated by X-ray diffractometer (XRD), UV-Vis spectrometer (UV-Vis), total organic carbon (TOC). The results revealed that the mechanisms of MB removal by gamma-MnO2 are significantly influenced by the pH. In acidic conditions, hypsochromic effects (i.e. blue shifts of UV-Vis spectra) resulting from N-demethylation of the dimethylamino group in MB may occur concomitantly with oxidative degradation by gamma-MnO2. However, the TOC in solution after gamma-MnO2 treatment in acidic conditions did not show a dramatic decrease. At near neutral pH conditions, there was almost no UV-Vis absorption for the MB solution, however, only 50% TOC removal was observed. It indicated that MB was not only adsorbed onto gamma-MnO2 but also partially oxidatively degraded to other organic compounds which were colourless for UV-Vis.