Antibiotics alter the metabolic profile of metolachlor in soil-plant system by disturbing the detoxifying process and oxidative stress.

Antibiotics are widely detected in farmland, which may influence the environmental behavior and risks of the coexisting pesticide. In this work, the effects of antibiotics on metolachlor transformation in soil-pea and the risk of metolachlor to earthworm were assessed, and the mechanism was explored in view of detoxifying process and oxidative stress. Antibiotics affected not the degradation rate but the metabolic profile of metolachlor. In soil, the content of metabolites oxaloacetic acid (OA) and ethane sulfonic acid (ESA) was decreased and dechlorometolachlor (DCL) was increased by antibiotics. In pea, the accumulation of metolachlor, DCL and ESA was decreased, while OA was increased by antibiotics. The changed transformation of metolachlor affected the risk to earthworm according to risk quote assessment. In further research, it was found that cytochrome P450 (CYP450) enzyme was reduced by 12.3% - 30.4% in soil and 12.4% - 23.6% in pea, which might due to excessive ROS accumulation induced by antibiotics, thus affecting the transformation and metabolite profile of metolachlor in soil-plant system.

Diversity analysis of sea anemone peptide toxins in different tissues of Heteractis crispa based on transcriptomics.

Peptide toxins found in sea anemones venom have diverse properties that make them important research subjects in the fields of pharmacology, neuroscience and biotechnology. This study used high-throughput sequencing technology to systematically analyze the venom components of the tentacles, column, and mesenterial filaments of sea anemone Heteractis crispa, revealing the diversity and complexity of sea anemone toxins in different tissues. A total of 1049 transcripts were identified and categorized into 60 families, of which 91.0% were proteins and 9.0% were peptides. Of those 1049 transcripts, 416, 291, and 307 putative proteins and peptide precursors were identified from tentacles, column, and mesenterial filaments respectively, while 428 were identified when the datasets were combined. Of these putative toxin sequences, 42 were detected in all three tissues, including 33 proteins and 9 peptides, with the majority of peptides being ShKT domain, ß-defensin, and Kunitz-type. In addition, this study applied bioinformatics approaches to predict the family classification, 3D structures, and functional annotation of these representative peptides, as well as the evolutionary relationships between peptides, laying the foundation for the next step of peptide pharmacological activity research.

Nitrogen fertiliser-domesticated microbes change the persistence and metabolic profile of atrazine in soil.

Pesticides and fertilisers are frequently used and may co-exist on farmlands. The overfertilisation of soil may have a profound influence on pesticide residues, but the mechanism remains unclear. The effects of chemical fertilisers on the environmental behaviour of atrazine and their underlying mechanisms were investigated. The present outcomes indicated that the degradation of atrazine was inhibited and the half-life was prolonged 6.0 and 7.6 times by urea and compound fertilisers (NPK) at 1.0 mg/g (nitrogen content), respectively. This result, which was confirmed in both sterilised and transfected soils, was attributed to the inhibitory effect of nitrogen fertilisers on soil microorganisms. The abundance of soil bacteria was inhibited by nitrogen fertilisers, and five families of potential atrazine degraders (Micrococcaceae, Rhizobiaceae, Bryobacteraceae, Chitinophagaceae, and Sphingomonadaceae) were strongly and positively (R > 0.8, sig < 0.05) related to the decreased functional genes (atzA and trzN), which inhibited hydroxylation metabolism and ultimately increased the half-life of atrazine. In addition, nitrogen fertilisers decreased the sorption and vertical migration behaviour of atrazine in sandy loam might increase the in-situ residual and ecological risk. Our findings verified the weakened atrazine degradation with nitrogen fertilisers, providing new insights into the potential risks and mechanisms of atrazine in the context of overfertilisation.

Synthesis and Hypoglycemic Effect of Insulin from the Venom of Sea Anemone Exaiptasia diaphana.

Sea anemone venom, abundant in protein and peptide toxins, serves primarily for predatory defense and competition. This study delves into the insulin-like peptides (ILPs) present in sea anemones, particularly focusing on their role in potentially inducing hypoglycemic shock in prey. We identified five distinct ILPs in Exaiptasia diaphana, exhibiting varied sequences. Among these, ILP-Ap04 was successfully synthesized using solid phase peptide synthesis (SPPS) to evaluate its hypoglycemic activity. When tested in zebrafish, ILP-Ap04 significantly reduced blood glucose levels in a model of diabetes induced by streptozotocin (STZ) and glucose, concurrently affecting the normal locomotor behavior of zebrafish larvae. Furthermore, molecular docking studies revealed ILP-Ap04's unique interaction with the human insulin receptor, characterized by a detailed hydrogen-bonding network, which supports a unique mechanism for its hypoglycemic effects. Our findings suggest that sea anemones have evolved sophisticated strategies to activate insulin receptors in vertebrates, providing innovative insights into the design of novel drugs for the treatment of diabetes.

First detection of Candidatus Rickettsia tarasevichiae in Hyalomma marginatum ticks.

Ticks are important vectors of zoonotic diseases and play a major role in the circulation and transmission of many rickettsial species. The aim of this study was to investigate the carriage of Candidatus Rickettsia tarasevichiae (CRT) in a total of 1168 ticks collected in Inner Mongolia to elucidate the potential public health risk of this pathogen, provide a basis for infectious disease prevention, control and prediction and contribute diagnostic ideas for clinical diseases that present with fever in populations exposed to ticks. A total of four tick species, Haemaphysalis concinna (n = 21), Dermacentor nuttalli (n = 122), Hyalomma marginatum (n = 148), and Ixodes persulcatus (n = 877), were collected at nine sampling sites in Inner Mongolia, China, and identified by morphological and molecular biological methods. Reverse transcription PCR targeting the 16S ribosomal RNA (rrs), gltA, groEL, ompB and Sca4 genes was used to detect CRT DNA. Sequencing was used for pathogen species confirmation. The molecular epidemiological analysis showed that three species of ticks were infected with CRT, and the overall positive rate was as high as 42%. The positive rate of I. persulcatus collected in Hinggan League city was up to 96%, and that of I. persulcatus collected in Hulun Buir city was 50%. The pool positive rates of D. nuttalli and H. marginatum collected in Bayan Nur city and H. concinna collected in Hulun Buir city were 0%, 28% and 40%, respectively. This study revealed the high prevalence of CRT infection in ticks from Inner Mongolia and the first confirmation of CRT detected in H. marginatum in China. The wide host range and high infection rate in Inner Mongolia may dramatically increase the exposure of CRT to humans and other vertebrates. The role of H. marginatum in the transmission of rickettsiosis and its potential risk to public health should be further considered.

Diversity and Evolutionary Analysis of Venom Insulin Derived from Cone Snails.

Cone snails possess a diverse array of novel peptide toxins, which selectively target ion channels and receptors in the nervous and cardiovascular systems. These numerous novel peptide toxins are a valuable resource for future marine drug development. In this review, we compared and analyzed the sequence diversity, three-dimensional structural variations, and evolutionary aspects of venom insulin derived from different cone snail species. The comparative analysis reveals that there are significant variations in the sequences and three-dimensional structures of venom insulins from cone snails with different feeding habits. Notably, the venom insulin of some piscivorous cone snails exhibits a greater similarity to humans and zebrafish insulins. It is important to emphasize that these venom insulins play a crucial role in the predatory strategies of these cone snails. Furthermore, a phylogenetic tree was constructed to trace the lineage of venom insulin sequences, shedding light on the evolutionary interconnections among cone snails with diverse diets.

FNIP1 abrogation promotes functional revascularization of ischemic skeletal muscle by driving macrophage recruitment.

Ischaemia of the heart and limbs attributable to compromised blood supply is a major cause of mortality and morbidity. The mechanisms of functional angiogenesis remain poorly understood, however. Here we show that FNIP1 plays a critical role in controlling skeletal muscle functional angiogenesis, a process pivotal for muscle revascularization during ischemia. Muscle FNIP1 expression is down-regulated by exercise. Genetic overexpression of FNIP1 in myofiber causes limited angiogenesis in mice, whereas its myofiber-specific ablation markedly promotes the formation of functional blood vessels. Interestingly, the increased muscle angiogenesis is independent of AMPK but due to enhanced macrophage recruitment in FNIP1-depleted muscles. Mechanistically, myofiber FNIP1 deficiency induces PGC-1α to activate chemokine gene transcription, thereby driving macrophage recruitment and muscle angiogenesis program. Furthermore, in a mouse hindlimb ischemia model of peripheral artery disease, the loss of myofiber FNIP1 significantly improved the recovery of blood flow. Thus, these results reveal a pivotal role of FNIP1 as a negative regulator of functional angiogenesis in muscle, offering insight into potential therapeutic strategies for ischemic diseases.

Enhanced Versatility in Thorium Removal: Mesoporous Silica-Coated Magnetic Nanoparticles Functionalized by Phenanthroline Diamide as a Selective Adsorbent.

In order to promote the sustainable development of nuclear energy through thorium (Th(IV)) recycling, we synthesized SiO2-coated magnetic functional nanocomposites (SiO2@Fe3O4) that were modified with 2,9-diamide-1,10-phenanthroline (DAPhen) to serve as an adsorbent for Th(IV) removal. SiO2@Fe3O4-DAPhen showed effective Th(IV) adsorption in both weakly and strongly acidic solutions. Owing to its porous structure that facilitated rapid adsorption kinetics, equilibrium was achieved within 5 and 0.5 min at pH 3 and 1 mol L-1 HNO3, respectively. In weakly acidic solutions, Th(IV) primarily formed chemical coordination bonds with DAPhen groups, while in strongly acidic solutions, the dominant interaction was electrostatic attraction. Density functional theory (DFT) calculations indicated that electrostatic attraction was weaker compared to chemical coordination, resulting in reduced diffusion resistance and consequently faster adsorption rates in strongly acidic solutions. Furthermore, SiO2@Fe3O4-DAPhen exhibited a high adsorption capacity for Th(IV); it removed Th(IV) through chelation and electrostatic attraction at pH 3 and 1 mol L-1 HNO3, with maximum adsorption capacities of 833.3 and 1465.7 mg g-1, respectively. SiO2@Fe3O4-DAPhen also demonstrated excellent tolerance to salinity, adsorption selectivity, and radiation resistance, thereby highlighting its practical potential for Th(IV) removal in diverse contaminated water sources. Hence, SiO2@Fe3O4-DAPhen represents a promising choice for the rapid and efficient removal of Th(IV).

Proteolytic rewiring of mitochondria by LONP1 directs cell identity switching of adipocytes.

Mitochondrial proteases are emerging as key regulators of mitochondrial plasticity and acting as both protein quality surveillance and regulatory enzymes by performing highly regulated proteolytic reactions. However, it remains unclear whether the regulated mitochondrial proteolysis is mechanistically linked to cell identity switching. Here we report that cold-responsive mitochondrial proteolysis is a prerequisite for white-to-beige adipocyte cell fate programming during adipocyte thermogenic remodelling. Thermogenic stimulation selectively promotes mitochondrial proteostasis in mature white adipocytes via the mitochondrial protease LONP1. Disruption of LONP1-dependent proteolysis substantially impairs cold- or ß3 adrenergic agonist-induced white-to-beige identity switching of mature adipocytes. Mechanistically, LONP1 selectively degrades succinate dehydrogenase complex iron sulfur subunit B and ensures adequate intracellular succinate levels. This alters the histone methylation status on thermogenic genes and thereby enables adipocyte cell fate programming. Finally, augmented LONP1 expression raises succinate levels and corrects ageing-related impairments in white-to-beige adipocyte conversion and adipocyte thermogenic capacity. Together, these findings reveal that LONP1 links proteolytic surveillance to mitochondrial metabolic rewiring and directs cell identity conversion during adipocyte thermogenic remodelling.

Existence of antibiotic pollutant in agricultural soil: Exploring the correlation between microbiome and pea yield.

Due to sewage irrigation, manure fertilizer application or other agricultural activities, antibiotics have been introduced into farmland as an emerging contaminant, existing with other agrochemicals. However, the potential influences of antibiotics on the efficiency of agrochemicals and crops health are still unclear. In this work, the effect of antibiotics on fertilization efficiency and pea yield was evaluated, and the mechanism was explored in view of soil microbiome. Nitrogen utilization and pea yield were decreased by antibiotics. In specific, the weight of seeds decreased 9.5 % by 5 mg/kg antibiotics and decreased 25.1 % by 50 mg/kg antibiotics. For N nutrient in pea, antibiotics resulted in 62.5 %-63.7 % decrease in amino acid content and 8.3 %-35.3 % decrease in inorganic-N content. Further research showed that antibiotics interfered with N cycle in soil, inhibiting urea decomposition and denitrification process by reducing function genes ureC, nirK and norB in soil, thus decreasing N availability. Meanwhile, antibiotics destroyed the enzyme function in N assimilation. This work evaluated the environmental risk of antibiotics from fertilization efficiency and N utilization in crop. Antibiotics could not only affect N cycle, limiting the decomposition of N fertilizer, but also affect N utilization in plants, thus affecting the yield and even the quality of leguminous crops.

Functionalized hierarchically porous carbon doped boron nitride for multipurpose and efficient treatment of radioactive sewage.

In order to recycle Uranium (U) for the sustainable development of nuclear energy, diamide bipyridine (DABP) modified hierarchically porous carbon doped boron nitride (BCN-DABP) was synthesized as an adsorbent for the multipurpose removal of U. BCN-DABP displayed good adsorption performance for U in both weakly and highly acidic solutions. The hierarchically porous structure endowed BCN-DABP with ultrafast adsorption kinetics, and adsorption reached equilibrium within 180.0 and 0.5 min under pH = 4.0 and 2.00 mol L-1 HNO3, respectively. Moreover, combination of adsorption isotherm studies and DFT calculations showed that BCN-DABP possessed high adsorption capacities for U and displayed different adsorption performance under different conditions. BCN-DABP adsorbed UO22+ by chelation and electrostatic attraction under pH 4.0 and 2.00 mol L-1 HNO3, the maximum adsorption capacity under two conditions reached 818.7 and 1296.7 mg g-1, respectively. As a result, BCN-DABP is expected to be used for the rapid and efficient removal of U in various kinds of contaminated water. Furthermore, excellent salinity tolerance, good adsorption selectivity, and outstanding radiation resistance also endowed BCN-DABP with great practical potential for removing U in radioactive contaminated water as well as high level liquid waste.

Mitochondrial proteostasis stress in muscle drives a long-range protective response to alleviate dietary obesity independently of ATF4.

Mitochondrial quality in skeletal muscle is crucial for maintaining energy homeostasis during metabolic stresses. However, how muscle mitochondrial quality is controlled and its physiological impacts remain unclear. Here, we demonstrate that mitoprotease LONP1 is essential for preserving muscle mitochondrial proteostasis and systemic metabolic homeostasis. Skeletal muscle-specific deletion of Lon protease homolog, mitochondrial (LONP1) impaired mitochondrial protein turnover, leading to muscle mitochondrial proteostasis stress. A benefit of this adaptive response was the complete resistance to diet-induced obesity. These favorable metabolic phenotypes were recapitulated in mice overexpressing LONP1 substrate ΔOTC in muscle mitochondria. Mechanistically, mitochondrial proteostasis imbalance elicits an unfolded protein response (UPRmt) in muscle that acts distally to modulate adipose tissue and liver metabolism. Unexpectedly, contrary to its previously proposed role, ATF4 is dispensable for the long-range protective response of skeletal muscle. Thus, these findings reveal a pivotal role of LONP1-dependent mitochondrial proteostasis in directing muscle UPRmt to regulate systemic metabolism.

Clinical Effectiveness of Laparoscopic Fiberoptic Choledochoscopy versus Conventional Open Surgery for Gallbladder Stones Complicated with Common Bile Duct Stones.

Objective: To assess the clinical effectiveness of laparoscopic fiberoptic choledochoscopy versus conventional open surgery for gallbladder stones complicated with common bile duct stones. Methods: In this retrospective study, 110 patients with gallbladder stones complicated with common bile duct stones treated in our institution between May 2018 and April 2020 were recruited and assigned to receive either open surgery (conventional group) or laparoscopic fiberoptic choledochoscopy (experimental group). Outcome measures included intraoperative indices, postoperative indices, postoperative complications, and changes in postoperative blood indices. Results: Laparoscopic fiberoptic choledochoscopy was associated with less intraoperative bleeding volume and a shorter surgical incision length versus open surgery (P < 0.05). All eligible patients showed similar operative time (P > 0.05). Laparoscopic fiberoptic choledochoscopy resulted in shorter postoperative exhaust time and mean length of stay and a higher mean hospitalization cost versus open surgery (P < 0.05). There was no significant difference in the number of patients with intensive care units (ICU) monitoring or primary suture of the common bile duct between the two groups (P > 0.05). The eligible patients after laparoscopic fiberoptic choledochoscopy experienced fewer complications versus those after open surgery (P < 0.05). Laparoscopic fiberoptic choledochoscopy had a milder impact on postoperative albumin decrease versus open surgery (P < 0.05). No significant difference was found in the postoperative leukocyte changes and total bilirubin decrease between the two groups (P > 0.05). Conclusion: Laparoscopic fiberoptic choledochoscopy has better perioperative indices outcomes, lower incidence of postoperative complications, smaller postoperative albumin changes, and superior overall performance versus conventional open surgery for gallbladder stones complicated with common bile duct stones.

FNIP1 regulates adipocyte browning and systemic glucose homeostasis in mice by shaping intracellular calcium dynamics.

Metabolically beneficial beige adipocytes offer tremendous potential to combat metabolic diseases. The folliculin interacting protein 1 (FNIP1) is implicated in controlling cellular metabolism via AMPK and mTORC1. However, whether and how FNIP1 regulates adipocyte browning is unclear. Here, we demonstrate that FNIP1 plays a critical role in controlling adipocyte browning and systemic glucose homeostasis. Adipocyte-specific ablation of FNIP1 promotes a broad thermogenic remodeling of adipocytes, including increased UCP1 levels, high mitochondrial content, and augmented capacity for mitochondrial respiration. Mechanistically, FNIP1 binds to and promotes the activity of SERCA, a main Ca2+ pump responsible for cytosolic Ca2+ removal. Loss of FNIP1 resulted in enhanced intracellular Ca2+ signals and consequential activation of Ca2+-dependent thermogenic program in adipocytes. Furthermore, mice lacking adipocyte FNIP1 were protected against high-fat diet-induced insulin resistance and liver steatosis. Thus, these findings reveal a pivotal role of FNIP1 as a negative regulator of beige adipocyte thermogenesis and unravel an intriguing functional link between intracellular Ca2+ dynamics and adipocyte browning.

Disuse-associated loss of the protease LONP1 in muscle impairs mitochondrial function and causes reduced skeletal muscle mass and strength.

Mitochondrial proteolysis is an evolutionarily conserved quality-control mechanism to maintain proper mitochondrial integrity and function. However, the physiological relevance of stress-induced impaired mitochondrial protein quality remains unclear. Here, we demonstrate that LONP1, a major mitochondrial protease resides in the matrix, plays a role in controlling mitochondrial function as well as skeletal muscle mass and strength in response to muscle disuse. In humans and mice, disuse-related muscle loss is associated with decreased mitochondrial LONP1 protein. Skeletal muscle-specific ablation of LONP1 in mice resulted in impaired mitochondrial protein turnover, leading to mitochondrial dysfunction. This caused reduced muscle fiber size and strength. Mechanistically, aberrant accumulation of mitochondrial-retained protein in muscle upon loss of LONP1 induces the activation of autophagy-lysosome degradation program of muscle loss. Overexpressing a mitochondrial-retained mutant ornithine transcarbamylase (ΔOTC), a known protein degraded by LONP1, in skeletal muscle induces mitochondrial dysfunction, autophagy activation, and cause muscle loss and weakness. Thus, these findings reveal a role of LONP1-dependent mitochondrial protein quality-control in safeguarding mitochondrial function and preserving skeletal muscle mass and strength, and unravel a link between mitochondrial protein quality and muscle mass maintenance during muscle disuse.

Microglial P2Y14 receptor contributes to central sensitization following repeated inflammatory dural stimulation.

BACKGROUND: Recent studies have indicated that P2Y receptors in spinal microglia play a role in the development of neuropathic and inflammatory pain. However, it remains unclear whether P2Y receptors in microglia are involved in the pathogenesis of migraine. Therefore, the aim of this study was to investigate the role of microglial P2Y14 receptor in trigeminal cervical complex (TCC) in migraine. METHODS: We used a rat model of migraine induced by repeated inflammatory stimulation of the dura and examined the expression of P2Y14 receptor in the TCC in migraine rats by Western Blotting and immunofluorescence staining. Then, we determined the effect of P2Y14 antagonist PPTN on inflammatory soup (IS)-induced mechanical allodynia, microglial activation and ERK expression in TCC. RESULTS: The expression level of P2Y14 receptor increased significantly in microglia in TCC after 4 or 7 days of repeated IS stimulation of the dura. Application of PPTN significantly attenuated the decrease of periorbital pain threshold in migraine model rats. In addition, repeated IS stimulation of the dura induced the activation of microglia and the phosphorylation of the ERK1/2 in microglia in TCC, which were abolished by the application of PPTN. CONCLUSION: Our findings suggest that the increased P2Y14 receptor in microglia in TCC play a crucial role in the generation of mechanical allodynia in migraine rat model. Furthermore, the activation of the P2Y14 receptor is involved in microglial activation and ERK phosphorylation as well. The P2Y14 receptor in microglia might be used as a potential target for migraine treatment.

IRE1α regulates skeletal muscle regeneration through Myostatin mRNA decay.

Skeletal muscle can undergo a regenerative process from injury or disease to preserve muscle mass and function, which is critically influenced by cellular stress responses. Inositol-requiring enzyme 1 (IRE1) is an ancient endoplasmic reticulum (ER) stress sensor and mediates a key branch of the unfolded protein response (UPR). In mammals, IRE1α is implicated in the homeostatic control of stress responses during tissue injury and regeneration. Here, we show that IRE1α serves as a myogenic regulator in skeletal muscle regeneration in response to injury and muscular dystrophy. We found in mice that IRE1α was activated during injury-induced muscle regeneration, and muscle-specific IRE1α ablation resulted in impaired regeneration upon cardiotoxin-induced injury. Gain- and loss-of-function studies in myocytes demonstrated that IRE1αacts to sustain both differentiation in myoblasts and hypertrophy in myotubes through regulated IRE1-dependent decay (RIDD) of mRNA encoding Myostatin, a key negative regulator of muscle repair and growth. Furthermore, in the mouse model of Duchenne muscular dystrophy (DMD), loss of muscle IRE1α resulted in augmented Myostatin signaling and exacerbated the dystrophic phenotypes. Thus, these results reveal a pivotal role for the RIDD output of IRE1α in muscle regeneration, offering new insight into potential therapeutic strategies for muscle loss diseases.

AMPK-dependent and -independent coordination of mitochondrial function and muscle fiber type by FNIP1.

Mitochondria are essential for maintaining skeletal muscle metabolic homeostasis during adaptive response to a myriad of physiologic or pathophysiological stresses. The mechanisms by which mitochondrial function and contractile fiber type are concordantly regulated to ensure muscle function remain poorly understood. Evidence is emerging that the Folliculin interacting protein 1 (Fnip1) is involved in skeletal muscle fiber type specification, function, and disease. In this study, Fnip1 was specifically expressed in skeletal muscle in Fnip1-transgenic (Fnip1Tg) mice. Fnip1Tg mice were crossed with Fnip1-knockout (Fnip1KO) mice to generate Fnip1TgKO mice expressing Fnip1 only in skeletal muscle but not in other tissues. Our results indicate that, in addition to the known role in type I fiber program, FNIP1 exerts control upon muscle mitochondrial oxidative program through AMPK signaling. Indeed, basal levels of FNIP1 are sufficient to inhibit AMPK but not mTORC1 activity in skeletal muscle cells. Gain-of-function and loss-of-function strategies in mice, together with assessment of primary muscle cells, demonstrated that skeletal muscle mitochondrial program is suppressed via the inhibitory actions of FNIP1 on AMPK. Surprisingly, the FNIP1 actions on type I fiber program is independent of AMPK and its downstream PGC-1α. These studies provide a vital framework for understanding the intrinsic role of FNIP1 as a crucial factor in the concerted regulation of mitochondrial function and muscle fiber type that determine muscle fitness.

Comparison of microbial communities and amino acid metabolites in different traditional fermentation starters used during the fermentation of Hong Qu glutinous rice wine.

Hong Qu glutinous rice wine (HQGRW) is produced from glutinous rice with the addition of the traditional fermentation starter Hong Qu (mainly Gutian Hong Qu and Wuyi Hong Qu) has been added. It is unpalatable and rejected by consumers because the bitter and umami tastes are too high. The objective of this study was to compare the dynamics of the microbial communities and amino acids especially those in the different traditional fermentation starters used during HQGRW fermentation, and elucidate the key microbes responsible for amino acids. Three widely-used types of Hong Qu starters were used which can make different bitterness and umami in our previous studies, namely, black Wuyi Hong Qu (WB), red Wuyi Hong Qu (WR), and Gutian Hong Qu (GT). The living dynamics of fungal and bacterial communities during the fermentation were determined by high-throughput sequencing and rRNA gene sequencing technology for the first time. The content of amino acids in the HQGRW were determined by reverse-phase high-performance liquid chromatography analysis. The results showed that there were differences between fungal communities during the fermentation process in Wuyi Hong Qu and Gutian Hong Qu starters and between bacterial communities during the fermentation process in the three types of starters. The amino acid content of the samples showed an increasing trend in each group. The total amino acids, as well as the bitter, sweet, umami, astringent amino acids, in the GT Hong Qu group increased more slowly during fermentation, as comparerd to those in WB and WR groups. Furthermore, Meyerozyma, Saccharomyces, Bacillus, Rhizopus, Pediococcus, Monascus, and Halomonas were strongly positively correlated with the content of bitter and umami amino acids (|r| > 0.6 with FDR adjusted P < 0.05) by Spearman's correlation analysis. To conclude, these findings may contribute to a better understanding of the bitter and umami amino acid production mechanism during traditional fermentation and helpful in improving the taste of HQGRW.

Histone methyltransferase MLL4 controls myofiber identity and muscle performance through MEF2 interaction.

Skeletal muscle depends on the precise orchestration of contractile and metabolic gene expression programs to direct fiber-type specification and to ensure muscle performance. Exactly how such fiber type-specific patterns of gene expression are established and maintained remains unclear, however. Here, we demonstrate that histone monomethyl transferase MLL4 (KMT2D), an enhancer regulator enriched in slow myofibers, plays a critical role in controlling muscle fiber identity as well as muscle performance. Skeletal muscle-specific ablation of MLL4 in mice resulted in downregulation of the slow oxidative myofiber gene program, decreased numbers of type I myofibers, and diminished mitochondrial respiration, which caused reductions in muscle fatty acid utilization and endurance capacity during exercise. Genome-wide ChIP-Seq and mRNA-Seq analyses revealed that MLL4 directly binds to enhancers and functions as a coactivator of the myocyte enhancer factor 2 (MEF2) to activate transcription of slow oxidative myofiber genes. Importantly, we also found that the MLL4 regulatory circuit is associated with muscle fiber-type remodeling in humans. Thus, our results uncover a pivotal role for MLL4 in specifying structural and metabolic identities of myofibers that govern muscle performance. These findings provide therapeutic opportunities for enhancing muscle fitness to combat a variety of metabolic and muscular diseases.