Myostatin regulates energy homeostasis through autocrine- and paracrine-mediated microenvironment communications.

Myostatin (MSTN) has long been recognized as a critical regulator of muscle mass. Recently, there has been an increasing interest in its role in metabolism. In our study, we specifically knocked out MSTN in brown adipose tissue (BAT) from mice (MSTNΔUCP1) and found that the mice gained more weight than controls when fed a high-fat diet, with progressive hepatosteatosis and impaired skeletal muscle activity. RNA-seq analysis indicated signatures of mitochondrial dysfunction and inflammation in the MSTN-ablation BAT. Further studies demonstrated that the the Kruppel-like factor 4 (KLF4) was responsible for the metabolic phenotypes observed, while FGF21 contributed to the microenvironment communication between adipocytes and macrophages induced by the loss of MSTN. Moreover, the MSTN-SMAD2/3-p38 signaling pathway mediated the expression of KLF4 and FGF21 in adipocytes. In summary, our findings suggest that brown adipocytes-derived MSTN regulates BAT thermogenesis via autocrine and paracrine effects on adipocytes or macrophages, ultimately regulating systemic energy homeostasis.

Differences in rectal amino acid levels determine bacteria-originated sex pheromone specificity in two closely related flies.

Sex pheromones are widely used by insects as a reproductive isolating mechanism to attract conspecifics and repel heterospecifics. Although researchers have obtained extensive knowledge about sex pheromones, little is known about the differentiation mechanism of sex pheromones in closely related species. Using Bactrocera dorsalis and Bactrocera cucurbitae as the study model, we investigated how the male-borne sex pheromones are different. The results demonstrated that both 2,3,5-trimethylpyrazine (TMP) and 2,3,5,6-tetramethylpyrazine (TTMP) were sex pheromones produced by rectal Bacillus in the two flies. However, the TMP/TTMP ratios were reversed, indicating sex pheromone specificity in the two flies. Bacterial fermentation results showed that different threonine and glycine levels were responsible for the preference of rectal Bacillus to produce TMP or TTMP. Accordingly, threonine (glycine) levels and the expression of the threonine and glycine coding genes were significantly different between B. dorsalis and B. cucurbitae. In vivo assays confirmed that increased rectal glycine and threonine levels by amino acid feeding could significantly decrease the TMP/TTMP ratios and result in significantly decreased mating abilities in the studied flies. Meanwhile, decreased rectal glycine and threonine levels due to RNAi of the glycine and threonine coding genes was found to significantly increase the TMP/TTMP ratios and result in significantly decreased mating abilities. The study contributes to the new insight that insects and their symbionts can jointly regulate sex pheromone specificity in insects, and in turn, this helps us to better understand how the evolution of chemical communication affects speciation.

Inhibition of macrophages inflammasome activation via autophagic degradation of HMGB1 by EGCG ameliorates HBV-induced liver injury and fibrosis.

Background: Liver fibrosis is a reversible wound-healing response that can lead to end-stage liver diseases without effective treatment, in which HBV infection is a major cause. However, the underlying mechanisms for the development of HBV-induced fibrosis remains elusive, and efficacious therapies for this disease are still lacking. In present investigation, we investigated the effect and mechanism of green tea polyphenol epigallocatechin-3-gallate (EGCG) on HBV-induced liver injury and fibrosis. Methods: The effect of EGCG on liver fibrosis was examined in a recombinant cccDNA (rcccDNA) chronic HBV mouse model by immunohistochemical staining, Sirius red and Masson's trichrome staining. The functional relevance between high mobility group box 1 (HMGB1) and inflammasome activation and the role of EGCG in it were analyzed by Western blotting. The effect of EGCG on autophagic flux was determined by Western blotting and flow cytometric analysis. Results: EGCG treatment efficiently was found to alleviate HBV-induced liver injury and fibrosis in a recombinant cccDNA (rcccDNA) chronic HBV mouse model, a proven suitable research platform for HBV-induced fibrosis. Mechanistically, EGCG was revealed to repress the activation of macrophage NLRP3 inflammasome, a critical trigger of HBV-induced liver fibrosis. Further study revealed that EGCG suppressed macrophage inflammasome through downregulating the level of extracellular HMGB1. Furthermore, our data demonstrated that EGCG treatment downregulated the levels of extracellular HMGB1 through activating autophagic degradation of cytoplasmic HMGB1 in hepatocytes. Accordingly, autophagy blockade was revealed to significantly reverse EGCG-mediated inhibition on extracellular HMGB1-activated macrophage inflammasome and thus suppress the therapeutic effect of EGCG on HBV-induced liver injury and fibrosis. Conclusion: EGCG ameliorates HBV-induced liver injury and fibrosis via autophagic degradation of cytoplasmic HMGB1 and the subsequent suppression of macrophage inflammasome activation. These data provided a new pathogenic mechanism for HBV-induced liver fibrosis involving the extracellular HMGB1-mediated macrophage inflammasome activation, and also suggested EGCG administration as a promising therapeutic strategy for this disease.

Gut bacteria induce oviposition preference through ovipositor recognition in fruit fly.

Gut bacteria play important roles in insect life cycle, and various routes can be used by insects to effectively transmit their gut bacteria. However, it is unclear if the gut bacteria can spread by actively attracting their insect hosts, and the recognition mechanisms of host insects are poorly understood. Here, we explore chemical interactions between Bactrocera dorsalis and its gut bacterium Citrobacter sp. (CF-BD). We found that CF-BD could affect the development of host ovaries and could be vertically transmitted via host oviposition. CF-BD could attract B. dorsalis to lay eggs by producing 3-hexenyl acetate (3-HA) in fruits that were hosts of B. dorsalis. Furthermore, we found that B. dorsalis could directly recognize CF-BD in fruits with their ovipositors in which olfactory genes were expressed to bind 3-HA. This work reports an important mechanism concerning the active spread of gut bacteria in their host insects.

PARP1 inhibition enhances reactive oxygen species on gut microbiota.

Poly(ADP-ribose) polymerase 1 (PARP1) plays a key role in genome stability by modulating DNA-damage responses. Activated by DNA interruptions through ultraviolet (UV) exposure, PARylation is synthesized by PARP1 and serves as a survival mechanism for cancer and metabolic diseases. Several strategies including ROS and antimicrobial peptides (AMPs) function in host defenses, while the targeted tissue and mechanism under DNA damage are unknown. Here, we show that DNA damage induces responses specifically in the gut tissue. The knockdown of PARP1 reduces the activation of PARylation. Parp1 knockdown under DNA damage results in over-accumulated ROS and secretion of AMPs through the regulation of Relish, a subunit of nuclear factor-κB (NF-κB). Double-knockdown of Parp1 and Relish specifically in the gut inhibits AMP secretion. In conclusion, the host defense is achieved through ROS accumulation rather than the AMPs under DNA damage. In contrast, the knockdown of PARP1 exacerbates ROS accumulation to a harmful level. Under this circumstance, NF-κb targeted AMP secretion is provoked for host defense. Microbiome and functional analysis provide evidence for the hazard of DNA damage and show variations in the metabolic pathways following Parp1 inhibition. Our findings suggest the notion that PARP1 inhibition contributes to ROS accumulation under DNA damage and its role in NF-κb activation for host defense.

The Efficacy of Tai Chi and Stretching Exercises Based on a Smartphone Application for Patients With Parkinson's Disease: A Protocol for a Randomized Controlled Trial.

Introduction: Parkinson's disease (PD) is a common neurodegenerative disease that seriously impairs patients' quality of life, and increases the burden of patients and caregivers. Both drugs and exercise can alleviate its motor and non-motor symptoms, improving the quality of life for PD patients. Telehealth, an increasingly popular tool, makes rehabilitation accessible at home, overcoming the inconvenience of traffic and scheduling. Care-PD is a phone application designed for rehabilitation training, which provides Tai Chi and stretching exercises through tutorial videos as well as an online evaluation system. In this protocol, we will explore the efficacy of Tai Chi and stretching exercises as a PD rehabilitation therapy based on the smartphone application Care-PD. Methods and Analysis: A double-blind, parallel randomized controlled trial will be conducted in this study. The recruitment, intervention, and evaluation processes will be implemented through the Care-PD application. Persons with PD will fill out questionnaires on Activities of Daily Living (ADL), upload the latest case report, and sign the informed consent form in the application. Afterward, doctors and researchers will screen and enroll 180 participants who will be randomly (1:1:1) assigned to Tai Chi group, stretching exercises group, or control group. The subjects will participate in a 1-h exercise session three times per week for 12 weeks, ending with another 4 weeks of follow-up study. Each exercise session includes 10 min of warm-up, 45 min of exercise, and 5 min of cool-down. The primary outcomes are Motor Aspects of Experiences of Daily Living and the 39-item Parkinson's disease Questionnaire. The secondary outcomes include the 9-item Wearing-Off Questionnaire, the Freezing of Gait Questionnaire, the Caregiver Strain Index, Non-motor Experiences of Daily Living, ADL, and Morse Fall Scale. All assessments will be performed at baseline, week 12 and 16. Discussion: Care-PD integrates subject recruitment, intervention, and evaluation, providing a new perspective on clinical rehabilitation for persons with PD. This study will evaluate the efficacy of Tai Chi and stretching exercises on patients' quality of life and disease progression based on a smartphone application. We aim to provide a new rehabilitation training platform for persons with PD. Ethics and Dissemination: This study was approved by the Scientific Research Ethics Committee (102772020RT132) of Shanghai University of Sport. Data collection begins after the approval of the ethics committee. The participants must sign an informed consent form before enrollment. The results will be published in relevant journals, seminars, and be disseminated among rehabilitation practitioners and patients with PD. Clinical Trial Registration: Chinese Clinical Trial Registry, identifier [ChiCTR2100042096]. Registered on January 13, 2021.

Egg-Surface Bacteria Are Indirectly Associated with Oviposition Aversion in Bactrocera dorsalis.

Finding a suitable oviposition site is a challenging task for a gravid female fly, because the hatched maggots have limited mobility, making it difficult to find an alternative host. The oriental fruit fly, Bactrocera dorsalis, oviposits on many types of fruits. Maggots hatching in a fruit that is already occupied by conspecific worms will face food competition. Here, we showed that maggot-occupied fruits deter B. dorsalis oviposition and that this deterrence is based on the increased ß-caryophyllene concentration in fruits. Using a combination of bacterial identification, volatile content quantification, and behavioral analyses, we demonstrated that the egg-surface bacteria of B. dorsalis, including Providencia sp. and Klebsiella sp., are responsible for this increase in the ß-caryophyllene contents of host fruits. Our research shows a type of tritrophic interaction between micro-organisms, insects, and insect hosts, which will provide considerable insight into the evolution of insect behavioral responses to volatile compounds.

Insight on mutation-induced resistance to anaplastic lymphoma kinase inhibitor ceritinib from molecular dynamics simulations.

Ceritinib, an advanced anaplastic lymphoma kinase (ALK) next-generation inhibitor, has been proved excellent antitumor activity in the treatment of ALK-associated cancers. However, the accumulation of acquired resistance mutations compromise the therapeutic efficacy of ceritinib. Despite abundant mutagenesis data, the structural determinants for reduced ceritinib binding in mutants remains elusive. Focusing on the G1123S and F1174C mutations, we applied molecular dynamics (MD) simulations to study possible reasons for drug resistance caused by these mutations. The MD simulations predict that the studied mutations allosterically impact the configurations of the ATP-binding pocket. An important hydrophobic cluster is identified that connects P-loop and the αC-helix, which has effects on stabilizing the conformation of ATP-binding pocket. It is suggested, in this study, that the G1123S and F1174C mutations can induce the conformational change of P-loop thereby causing the reduced ceritinib affinity and causing drug resistance.

Conformational Transition of Key Structural Features Involved in Activation of ALK Induced by Two Neuroblastoma Mutations and ATP Binding: Insight from Accelerated Molecular Dynamics Simulations.

Deregulated kinase activity of anaplastic lymphoma kinase (ALK) has been observed to be implicated in the development of tumor progression. The activation mechanism of ALK is proposed to be similar to other receptor tyrosine kinases (RTKs), but the distinct static X-ray crystal conformation of ALK suggests its unique conformational transition. Herein, we have illustrated the dynamic conformational property of wild-type ALK as well as the kinase activation equilibrium variation induced by two neuroblastoma mutations (R1275Q and Y1278S) and ATP binding by performing enhanced sampling accelerated Molecular Dynamics (aMD) simulations. The results suggest that the wild-type ALK is mostly favored in the inactive state, whereas the mutations and ATP binding promote a clear shift toward the active-like conformation. The R1275Q mutant stabilizes the active conformation by rigidifying the αC-in conformation. The Y1278S mutant promotes activation at the expense of a π-stacking hydrophobic cluster, which plays a critical role in the stabilization of the inactive conformation of native ALK. ATP produces a more compact active site and thereby facilitates the activation of ALK. Taken together, these findings not only elucidate the diverse conformations in different ALKs but can also shed light on new strategies for protein engineering and structural-based drug design for ALK.

A molecular dynamics investigation into the mechanisms of alectinib resistance of three ALK mutants.

Alectinib, a highly selective next-genetation anaplastic lymphoma kinase (ALK) inhibitor, has demonstrated promising antitumor activity in patients with ALK-positive non-small cell lung carcinomas (NSCLC). However, the therapeutic benefits of alectinib is inescapably hampered by the development of acquired resistant mutations in ALK. Despite the availability of ample experimental mutagenesis data, the molecular origin and the structural motifs under alectinib binding affinity deficiencies are still ambiguous. Here, molecular dynamics (MD) simulations and molecular mechanics generalized born surface area (MM-GBSA) calculation approaches were employed to elucidate the mechanisms of alectinib resistance induced by the mutations I1171N, V1180L, and L1198F. The MD results reveal that the studied mutations could trigger the dislocation of alectinib as well as conformational changes at the inhibitor binding site, thus induce the interactional changes between alectinib and mutants. The most influenced regions are the ligand binding entrance and the hinge region, which are considered to be the dominant binding motifs accounting for the binding affinity loss in mutants. The "key and lock mechanism" between the ethyl group at position 9 of alectinib and a recognition cavity in the hinge region of ALK is presented to illustrate the major molecular origin of drug resistance. Our results provide mechanistic insight into the effect of ALK mutations resistant to alectinib, which could contribute to further rational design of inhibitors to combat the acquired resistance.

The plant pathogen Gluconobacter cerinus strain CDF1 is beneficial to the fruit fly Bactrocera dorsalis.

Plant pathogens can build relationships with insect hosts to complete their life cycles, and they often modify the behavior and development of hosts to improve their own fitness. In order to unravel whether some bacteria that can make fruit rot could have developed symbiotic interactions with Bactrocera dorsalis, we studied the symbiont bacteria profiles of the fly. We identified the bacterium Gluconobacter cerinus strain CDF1 from the ovaries and eggs of the oriental fruit fly B. dorsalis and the amount of Gluconobacter cerinus strain CDF1 increased significantly as the ovaries developed and in fruits on which non-sterile eggs were laid. Gluconobacter cerinus strain CDF1 addition to bananas fastens the rotting process and its addition to the eggs fastens their development/hatching rate. All in all, our data suggest that Gluconobacter cerinus strain CDF1 is beneficial to the fruit fly.

Performance of the biological aerated filter bioaugmented by a yeast Magnusiomyces ingens LH-F1 for treatment of Acid Red B and microbial community dynamics.

Biological aerated filters (BAFs) were constructed and operated for assessing the effectiveness of bacterial community bioaugmented by a yeast Magnusiomyces ingens LH-F1 for treatment of azo dye Acid Red B (ARB). Dynamics of both bacterial and fungal communities were analyzed through MiSeq sequencing method. The results showed that the bioaugmented BAF displayed obviously better performance for decolorization, COD removal and detoxification of ARB wastewater than the other two which were inoculated with activated sludge (AS) and single M. ingens LH-F1, respectively. Moreover, the bioaugmented BAF also exhibited higher tolerance and stability to shock loading. MiSeq sequencing results demonstrated that both of bacterial and fungal communities remarkably shifted with operation conditions, and the increasing fungal diversity in the bioaugmented BAF was probably related to the relatively high biodegradation and detoxification efficiency. Furthermore, M. ingens LH-F1 survived in the bioaugmented BAF and became one of the dominant fungal species. Therefore, bioaugmentation with yeast M. ingens LH-F1 was successful for improving traditional biological processes aiming at treatment of azo compounds. This method was also potentially useful and meaningful for treating other recalcitrant organic pollutants in practical applications.

Aerobic decolorization, degradation and detoxification of azo dyes by a newly isolated salt-tolerant yeast Scheffersomyces spartinae TLHS-SF1.

Isolation, identification and characterization of a salt-tolerant yeast capable of degrading and detoxifying azo dyes were investigated in this study. Possible degradation pathway of Acid Scarlet 3R was proposed through analyzing metabolic intermediates using UV-Vis and HPLC-MS methods. Furthermore, the Microtox test was performed to evaluate the acute toxicity of the dye before and after biodegradation. The results showed that a salt-tolerant yeast named TLHS-SF1 was isolated and identified as Scheffersomyces spartinae basing on 26S rDNA analysis. The optimal decolorization and growth parameters were: sucrose 2 g L(-1), (NH4)2SO4 0.6 g L(-1), yeast extract 0.08 g L(-1), NaCl ⩽ 30 g L(-1), 160 rmin(-1), 30 °C and pH 5.0-6.0. More than 90% of 80 mg L(-1) 3R could be decolorized within 16 h under the optimal conditions. 3R was possibly degraded successively through azo-reduction, deamination and desulfonation pathways, and its acute toxicity obviously decreased by strain TLHS-SF1.