Microbiota derived D-malate inhibits skeletal muscle growth and angiogenesis during aging via acetylation of Cyclin A.

Metabolites derived from the intestinal microbiota play an important role in maintaining skeletal muscle growth, function, and metabolism. Here, we found that D-malate (DMA) is produced by mouse intestinal microorganisms and its levels increase during aging. Moreover, we observed that dietary supplementation of 2% DMA inhibits metabolism in mice, resulting in reduced muscle mass, strength, and the number of blood vessels, as well as the skeletal muscle fiber type I/IIb ratio. In vitro assays demonstrate that DMA decreases the proliferation of vascular endothelial cells and suppresses the formation of blood vessels. In vivo, we further demonstrated that boosting angiogenesis by muscular VEGFB injection rescues the inhibitory effects of D-malate on muscle mass and fiber area. By transcriptomics analysis, we identified that the mechanism underlying the effects of DMA depends on the elevated intracellular acetyl-CoA content and increased Cyclin A acetylation rather than redox balance. This study reveals a novel mechanism by which gut microbes impair muscle angiogenesis and may provide a therapeutic target for skeletal muscle dysfunction in cancer or aging.

Exercise-induced α-ketoglutaric acid stimulates muscle hypertrophy and fat loss through OXGR1-dependent adrenal activation.

Beneficial effects of resistance exercise on metabolic health and particularly muscle hypertrophy and fat loss are well established, but the underlying chemical and physiological mechanisms are not fully understood. Here, we identified a myometabolite-mediated metabolic pathway that is essential for the beneficial metabolic effects of resistance exercise in mice. We showed that substantial accumulation of the tricarboxylic acid cycle intermediate α-ketoglutaric acid (AKG) is a metabolic signature of resistance exercise performance. Interestingly, human plasma AKG level is also negatively correlated with BMI. Pharmacological elevation of circulating AKG induces muscle hypertrophy, brown adipose tissue (BAT) thermogenesis, and white adipose tissue (WAT) lipolysis in vivo. We further found that AKG stimulates the adrenal release of adrenaline through 2-oxoglutarate receptor 1 (OXGR1) expressed in adrenal glands. Finally, by using both loss-of-function and gain-of-function mouse models, we showed that OXGR1 is essential for AKG-mediated exercise-induced beneficial metabolic effects. These findings reveal an unappreciated mechanism for the salutary effects of resistance exercise, using AKG as a systemically derived molecule for adrenal stimulation of muscle hypertrophy and fat loss.

Relationship Between Sleep Problems and Memory Impairment Among Nurses.

BACKGROUND: Sleep problems are common among nurses and can lead to various health problems. Further, the relationship between multiple sleep problems and memory impairment in clinical nurses remains unknown. Therefore, in this study, we aimed to explore the relationship between sleep problems and memory impairment among nurses. METHODS: Multistage cluster-stratified random sampling was performed from tertiary hospitals in Shandong, China. Overall, a total of 1833 nurses were included in the final analysis. The Chinese version of the Pittsburgh Sleep Quality Index and prospective and retrospective memory questionnaire were administered to the participants. RESULTS: The sleep quality of the nurses decreased during the normal epidemic prevention and control period compared with that before the epidemic in terms of sleep duration, sleep efficiency, and sleep disturbances. Nurses who reported cumulative or specific sleep problems (e.g., high sleep latency, sleep disturbances, and daytime dysfunction) and those in the "daily disturbances" and "poor sleep quality" groups had a higher risk of memory impairment than the others. CONCLUSION: Sleep problems might be important for memory impairment among nurses. These findings may help identify nurses at considerable risk of memory impairment in clinical practice.

TLR4 in POMC neurons regulates thermogenesis in a sex-dependent manner.

The rising prevalence of obesity has become a worldwide health concern. Obesity usually occurs when there is an imbalance between energy intake and energy expenditure. However, energy expenditure consists of several components, including metabolism, physical activity, and thermogenesis. Toll-like receptor 4 (TLR4) is a transmembrane pattern recognition receptor, and it is abundantly expressed in the brain. Here, we showed that pro-opiomelanocortin (POMC)-specific deficiency of TLR4 directly modulates brown adipose tissue thermogenesis and lipid homeostasis in a sex-dependent manner. Deleting TLR4 in POMC neurons is sufficient to increase energy expenditure and thermogenesis resulting in reduced body weight in male mice. POMC neuron is a subpopulation of tyrosine hydroxylase neurons and projects into brown adipose tissue, which regulates the activity of sympathetic nervous system and contributes to thermogenesis in POMC-TLR4-KO male mice. By contrast, deleting TLR4 in POMC neurons decreases energy expenditure and increases body weight in female mice, which affects lipolysis of white adipose tissue (WAT). Mechanistically, TLR4 KO decreases the expression of the adipose triglyceride lipase and lipolytic enzyme hormone-sensitive lipase in WAT in female mice. Furthermore, the function of immune-related signaling pathway in WAT is inhibited because of obesity, which exacerbates the development of obesity reversely. Together, these results demonstrate that TLR4 in POMC neurons regulates thermogenesis and lipid balance in a sex-dependent manner.

An acyl-adenylate mimic reveals the structural basis for substrate recognition by the iterative siderophore synthetase DesD.

Siderophores are conditionally essential metabolites used by microbes for environmental iron sequestration. Most Streptomyces strains produce hydroxamate-based desferrioxamine (DFO) siderophores composed of repeating units of N1-hydroxy-cadaverine (or N1-hydroxy-putrescine) and succinate. The DFO biosynthetic operon, desABCD, is highly conserved in Streptomyces; however, expression of desABCD alone does not account for the vast structural diversity within this natural product class. Here, we report the in vitro reconstitution and biochemical characterization of four DesD orthologs from Streptomyces strains that produce unique DFO siderophores. Under in vitro conditions, all four DesD orthologs displayed similar saturation steady-state kinetics (Vmax = 0.9-2.5 µM⋅min-1) and produced the macrocyclic trimer DFOE as the favored product, suggesting a conserved role for DesD in the biosynthesis of DFO siderophores. We further synthesized a structural mimic of N1-hydroxy-N1-succinyl-cadaverine (HSC)-acyl-adenylate, the HSC-acyl sulfamoyl adenosine analog (HSC-AMS), and obtained crystal structures of DesD in the ATP-bound, AMP/PPi-bound, and HSC-AMS/Pi-bound forms. We found HSC-AMS inhibited DesD orthologs (IC50 values = 48-53 µM) leading to accumulation of linear trimeric DFOG and di-HSC at the expense of macrocyclic DFOE. Addition of exogenous PPi enhanced DesD inhibition by HSC-AMS, presumably via stabilization of the DesD-HSC-AMS complex, similar to the proposed mode of adenylate stabilization where PPi remains buried in the active site. In conclusion, our data suggest that acyl-AMS derivatives may have utility as chemical probes and bisubstrate inhibitors to reveal valuable mechanistic and structural insight for this unique family of adenylating enzymes.

Comparison of Safety and Outcomes between Endoscopic and Surgical Resections of Intermediate-Risk Primary Gastric Gastrointestinal Stromal Tumors.

BACKGROUND AND AIMS: The objective of this study was to compare the safety and efficacy of endoscopic resection with surgical resection in the treatment of intermediate-risk gastric gastrointestinal stromal tumors (GISTs) and to further evaluate whether imatinib adjuvant treatment is necessary for resected intermediate-risk gastric GIST by ER. METHODS: We retrospectively studied 128 cases for intermediate-risk gastric GISTs that were distributed in endoscopic (n = 33) and surgical groups (n = 95) at our center between December 2009 to July 2020. We statistically compared the clinical features, pathological reports, perioperative data, and long-term follow-up outcomes. RESULTS: Compared with the surgery group, the endoscopy group was associated with smaller tumor size (2.4 ± 1.0 vs. 6.0 ± 1.7 cm, p < 0.001), shorter operating time (67.3 ± 36.5 vs. 145.9 ± 74.8 min, p < 0.001), fewer incidence of short-term postoperative complications (3% vs. 32.6%, p = 0.002). Shorter postoperative hospital days (4.5 ± 1.4 vs. 8.5 ± 2.4 days, p < 0.001), shorter gastric functional recovery time (p < 0.001), and a lower overall medical cost of hospitalization (p < 0.001) was detected in the endoscopy group. During the median 44.5 months follow-up period, there were no cases of recurrence, metastasis, and death in the endoscopy group. Among 128 patients, 68 accepted adjuvant therapy with imatinib after resection. It was observed that the OS of the adjuvant treatment group with imatinib was lower than that of the group without imatinib (p = 0.033). CONCLUSION: Endoscopic resection for intermediate-risk gastric GIST is a feasible and safe method, and there is no significant benefit for patients with intermediate-risk gastric GIST to accept imatinib adjuvant treatment after ER.

Risk factors of perforation in gastric stromal tumors during endoscopic resection: a retrospective case-control study.

BACKGROUND AND AIMS: Perforation is a common complication during endoscopic resection (ER) of gastric gastrointestinal stromal tumors (gGISTs) associated with secondary infections, sepsis, hospitalization time and cost. However, the risk factors of perforation remain controversial. This study aimed to investigate the risk factors for perforation during ER of gGISTs. METHODS: This retrospective case-control study included consecutive patients with gGISTs who underwent ER between June 2009 and November 2021 at the Nanjing Drum Tower Hospital. Univariate and multivariate analyses were performed to investigate the risk factors for perforation. Sensitivity analyses with propensity scoring (PS) were performed to evaluate the stability of the independent effects. RESULTS: In total, 422 patients with gGISTs were included. The following factors were associated with perforation during ER: in the non-intraluminal growth patterns (all confounders adjusted odds ratio [aOR]: 5.39, 95% CI 2.99-9.72, P < 0.001), in the gastric fundus (aOR 2.25, 95% CI 1.40-3.60, P = 0.007), sized ≥ 2 cm (aOR 1.70, 95% CI 1.04-2.77, P = 0.035), in the lesser curvature (aOR 0.12, 95% CI 0.05-0.27, P < 0.001), and in the gastric cardia (aOR 0.13, 95% CI 0.04-0.50, P = 0.003). The PS analysis confirmed the stable independent effects of these identified risk factors. CONCLUSIONS: ERs of gGISTs in non-intraluminal growth patterns, in the gastric fundus, and with larger tumor size were independent risk factors for perforation. While tumors in the lesser curvature or gastric cardia were independent protective factor for perforation.

Porcine Epidemic Diarrhea Virus Membrane Protein Interacted with IRF7 to Inhibit Type I IFN Production during Viral Infection.

Porcine epidemic diarrhea virus (PEDV) is a highly pathogenic porcine enteropathogenic coronavirus causing severe enteritis and lethal watery diarrhea in piglets. PEDV infection suppresses the synthesis of type I IFN, and multiple viral proteins of PEDV have been shown to target the adaptors of innate immune pathways to inhibit type I IFN production. In this study, we identified PEDV membrane (M) protein as a new antagonist of type I IFN production in both human embryonic kidney HEK293T cells and porcine kidney PK-15 cells and determined the antagonistic mechanism used by M protein to target IFN regulatory factor 7 (IRF7), an important regulator of type I IFN production. IRF7 is phosphorylated and activated by TBK1 and IKKε in response to viral infection. We found that PEDV M protein interacted with the inhibitory domain of IRF7 and significantly suppressed TBK1/IKKε-induced IRF7 phosphorylation and dimerization of IRF7, leading to the decreased expression of type I IFN, although it did not affect the interaction between TBK1/IKKε and IRF7. As expected, overexpression of M protein significantly increased PEDV replication in porcine cells. The M proteins of both epidemic PEDV strains and vaccine strain showed similar antagonistic effect on type I IFN production, and the 1-55 region of M protein was essential for disruption of IRF7 function by interacting with IRF7. Taken together, our data identified a new, to our knowledge, IFN antagonist of PEDV, as well as a novel, to our knowledge, antagonistic mechanism evolved by PEDV to inhibit type I IFN production.

Comparison of endoscopic full-thickness resection and cap-assisted endoscopic full-thickness resection in the treatment of small (≤1.5 cm) gastric GI stromal tumors.

BACKGROUND AND AIMS: With the increasing incidence of small GI stromal tumors (GISTs), endoscopic full-thickness resection (EFTR) and cap-assisted EFTR (EFTR-C) have been suggested as 2 effective resection methods. We aimed to compare the outcomes of EFTR and EFTR-C for the treatment of small (≤1.5 cm) gastric GISTs. METHODS: This retrospective study included 67 patients who underwent EFTR and 46 patients who underwent EFTR-C at Nanjing Drum Tower Hospital. Clinicopathologic features, adverse events (AEs), and outcomes were compared between the 2 groups. Univariate and multivariate linear and logistic regressions were used to analyze the effects of the procedure on the therapeutic outcomes of patients and adjusted for covariates in the multivariate analysis. RESULTS: The tumor size in the EFTR group tended to be larger (P = .005). The resection time in the EFTR-C group was shorter than that in the EFTR group (38.3 ± 20.7 minutes vs 15.0 ± 11.8 minutes, P < .001), which retained statistical significance with adjustment for the covariates (adjusted mean difference, 22.2; 95% confidence interval, 15.0-29.4; P < .001). The R0 resection rate of the EFTR group was 94.0% and of the EFTR-C group 97.8% (P = .355). The EFTR-C group was superior to the EFTR group in terms of perioperative therapeutic outcomes, AEs, and postoperative recovery. No recurrence occurred in the EFTR and EFTR-C groups. CONCLUSIONS: EFTR-C was found to be the preferable technique for small (≤1.5 cm) gastric GISTs with shorter operation times, lower AEs, faster postoperative recovery, and shorter hospitalization times as compared with EFTR.

Multifunctional P450 Monooxygenase CftA Diversifies the Clifednamide Pool through Tandem C-H Bond Activations.

Polycyclic tetramate macrolactams (PTMs) are a class of structurally complex hybrid polyketide-nonribosomal peptide (PK-NRP) natural products produced by diverse bacteria. Several PTMs display pharmaceutically interesting bioactivities, and the early stages of PTM biosynthesis involving polyketide synthase (PKS) and nonribosomal peptide synthetase (NRPS) enzymology are well studied. However, the timing and mechanisms of post PKS-NRPS oxidations by P450 monooxygenases encoded in PTM biosynthetic gene clusters (BGCs) remain poorly characterized. Here we demonstrate that CftA, encoded in clifednamide-type PTM BGCs, is a multifunctional P450 monooxygenase capable of converting the C29-C30 ethyl side chain of ikarugamycin to either a C29-C30 methyl ketone or a C29-C30 hydroxymethyl ketone through C-H bond activation, resulting in the formation of clifednamide A or clifednamide C, respectively. We also report the complete structure of clifednamide C solved via multidimensional NMR (COSY, HSQC, HMBC, NOESY, and TOCSY) using material purified from an engineered Streptomyces strain optimized for production. Finally, the in vitro reconstitution of recombinant CftA catalytic activity revealed the oxidation cascade for sequential conversion of ikarugamycin to clifednamide A and clifednamide C. Our findings confirm prior genetics-based predictions on the origins of clifednamide complexity via P450s encoded in PTM BGCs and place CftA into a growing group of multifunctional P450s that tailor PTM natural products through late-stage regioselective C-H bond activation.

Treatment try of simulated agricultural surface runoff pollution by using a novel biomass concentrator reactor.

Increased agricultural surface runoff in rural watersheds is a leading cause of nonpoint source pollution. In this study, a new biomass concentrator reactor (BCR) is conducted to degrade simulated agricultural surface runoff for both start-up process and treatment process. The results show that both in the start-up phase and in the stable phase, BCR had a good degradation effect on simulated agricultural surface runoff. Within 13 days-15 days of completed start-up of BCR, degradation of COD can be considered to the first-order kinetics: lnCt=lnC0-0.1377t (R2 = 0.78). During the stabilization phase, the average removal rate of COD, NH4+-N, NO3--N, TN and TP from the effluents through the BCR membrane was 94.58%, 85.79%, 53.58%, 37.87%, and 60.62%, respectively, which was increased by 7.4%, 2.5%, 5.1%, 0.18% and 11.4%, respectively, compared to control experiment which the effluents without membrane. The pollutants degradation by BCR in stable phase show a partly relative model of Lawrence-McCarty equation, which the nitrogen and phosphorus degradation is vN=(4.1+S)/(2.53×S) (R2 = 0.69) and vP=(8.78+S)/(3.0×S) (R2 = 0.67), respectively. In the stable phase, the operation cost of BCR is about $0.08/(L•d). Future research on improved BCR maybe focus on the membrane pollution and cleaning, optimized operation conditions, new materials of membrane.

Simvastatin-loaded liposome nanoparticles treatment for uterine leiomyoma in a patient-derived xenograft mouse model: a pilot study.

Uterine leiomyomas are complex tumours with limited medical treatment options. Simvastatin is used to treat hypercholesterolaemia and has shown promising effects as a treatment option for leiomyomas. Previously, our group demonstrated a promising effect of simvastatin treatment in a patient-derived xenograft mouse model. Here, we tested the efficacy of simvastatin liposomal nanoparticles (NPs). After bilateral leiomyoma xenograft implantation, mice (N = 12) were divided into three treatment arms: control, simvastatin and simvastatin-loaded liposome NPs (simvastatin-NPs). Treatment with simvastatin significantly reduced tumour volume and inhibited the Ki67 expression when compared to the control group. There was a trend of reduced tumour volume and Ki67 expression after treatment with simvastatin-NP; however, the results were not significant. Due to low bioavailability and short half-life of simvastatin, liposomal NPs have the potential to enhance drug delivery, however, in this study NP did not provide improvement over simvastatin, but did demonstrate their potential for the delivery of simvastatin.Impact statementWhat is already known on this subject? Simvastatin treatment in a patient-derived xenograft mouse model reduced tumour growth and decreased proliferation.What do the results of this study add? Treatment with simvastatin significantly reduced tumour volume and inhibited the Ki67 expression when compared to the control group. There was a trend of reduced tumour volume and Ki67 expression after treatment with simvastatin-NP, however, it did not improve the efficacy of simvastatin at reducing tumour growth and proliferation.What are the implications of these findings for clinical practice and/or further research? More studies are needed to optimise the formulation of NPs to further enhance the sustainable delivery of simvastatin.

Succinate induces skeletal muscle fiber remodeling via SUNCR1 signaling.

The conversion of skeletal muscle fiber from fast twitch to slow-twitch is important for sustained and tonic contractile events, maintenance of energy homeostasis, and the alleviation of fatigue. Skeletal muscle remodeling is effectively induced by endurance or aerobic exercise, which also generates several tricarboxylic acid (TCA) cycle intermediates, including succinate. However, whether succinate regulates muscle fiber-type transitions remains unclear. Here, we found that dietary succinate supplementation increased endurance exercise ability, myosin heavy chain I expression, aerobic enzyme activity, oxygen consumption, and mitochondrial biogenesis in mouse skeletal muscle. By contrast, succinate decreased lactate dehydrogenase activity, lactate production, and myosin heavy chain IIb expression. Further, by using pharmacological or genetic loss-of-function models generated by phospholipase Cß antagonists, SUNCR1 global knockout, or SUNCR1 gastrocnemius-specific knockdown, we found that the effects of succinate on skeletal muscle fiber-type remodeling are mediated by SUNCR1 and its downstream calcium/NFAT signaling pathway. In summary, our results demonstrate succinate induces transition of skeletal muscle fiber via SUNCR1 signaling pathway. These findings suggest the potential beneficial use of succinate-based compounds in both athletic and sedentary populations.

Carbon dioxide and methane emission of denitrification bioreactor filling waste sawdust and industrial sludge for treatment of simulated agricultural surface runoff.

Carbon dioxide (CO2) and methane (CH4) produced by denitrification bioreactors in processing agricultural surface runoff have contributed to increasing proportion of greenhouse gases (GHG) emissions. It is the first time to monitor and quantify the emission flux of CO2 and CH4 produced by laboratory-scale denitrification bioreactors which recycled waste Cunninghamia lanceolata sawdust (CLS) and industrial sludge (IS) as fillers to process simulated agricultural surface runoff. Sludge-water ratio, inflow rate and water flow direction are used as experimental factors to study the effect on the emission flux of CO2 and CH4. Results show that emission flux of CO2 from denitrification bioreactors with different sludge-water ratio approached 20 mg m-2h-1, simultaneously the average emission flux of CH4 produced by all bioreactors was 1.785 mg m-2h-1. The addition of sludge increased the emission flux of CH4 and had no significant effect on the emission flux of CO2. Increasing the inflow rate reduced the CO2 emission flux from 21.57 to 1.27 mg m-2h-1, and at the same time increased the CH4 emission flux from 0.007 to 9.54 mg m-2h-1. The gravity flow of wastewater reduced the emission flux of CO2 and CH4. The emissions of CO2 and CH4 from folded plate denitrification bioreactor with CLS and industrial sludge with a volume ratio of 1:2 can be reduced by 24.67% and 73.3%, respectively. There was no need to add special gas collection and treatment devices because CO2 and CH4 emission fluxes produced by the folded plate denitrification bioreactor and gravity denitrification bioreactor are not enough to increase the greenhouse effect. This study quantified the CO2 and CH4 produced by denitrification bioreactors filling CLS and IS, and provided a reference for future research on the gases produced by the denitrification process.

Protective Effects of Naringin in Cerebral Infarction and Its Molecular Mechanism.

BACKGROUND Cerebral infarction is a cardiovascular disease with high morbidity and mortality. At present, many studies have reported the treatment of cerebral infarction by traditional Chinese medicine. Naringin, a flavonoid, is a major traditional Chinese medicine. However, the effect and mechanism of naringin on cerebral infarction is unclear. MATERIAL AND METHODS In our study, we established a rat model of cerebral infarction through middle cerebral artery occlusion (MCAO) to study the influence of naringin on cerebral infarction in vivo. After treatment with naringin, brain water content was detected to assess brain edema. Cerebral infarction volume and neurological deficits were also measured. Production of the inflammatory factors tumor necrosis factor (TNF)-alpha and interleukin (IL)-6) was measured using enzyme-linked immunosorbent assay (ELISA). Besides, the effect of naringin on cerebral infarction was investigated in vitro by establishing an oxygen-glucose deprivation (OGD) model in neuronal cells. Cell apoptosis and cell viability was determined using flow cytometry and MTT assay. RESULTS We found that naringin pretreatment significantly decreased the brain water content, cerebral infarction volume, and neurological deficit scores of MCAO subjected rats. And naringin treatment reduced apoptosis of nerve cells in rat hippocampus and the secretion of inflammatory factor such as TNF-alpha and IL-6. Besides, we found that naringin increased cell viability and inhibited apoptosis in OGD induced neuronal cells. Finally, we found that naringin promoted the expression of p-AKT protein in a concentration-dependent manner and activated the PI3K/AKT pathway in OGD induced neurons. CONCLUSIONS Naringin played a protective role in cerebral infarction via suppressing neuronal apoptosis and inflammation.

Transverse process anatomy as a guide to vertebral artery exposure during anterior cervical spine approach: A Cadaveric Study.

Safe exposure of the vertebral artery (VA) is needed during resection of tumors close to the artery and during repair of lacerations. We defined the anatomy of the anterior root of each transverse process (TP) from C3 to C6 for identification and exposure of the VA during the anterior approach. We examined the anatomy of the TP and assessed two approaches for safe identification of the VA, lateral to medial and medial to lateral dissection of the TP, in 20 cadavers. The safe zone at each level of the cervical spine was defined as an area in which the surgeon can start to dissect at the midline of that level on the TP and safely cross the VA laterally. For the lateral to medial approach the surgical safe zone lies between the mid axis of the TPs and a line 2 mm parallel to and above it. The average TP angle was 11 ± 10.2 degrees. The mean distance of the lateral border of the VA from the TP tip was 3.78-5.28 mm. For the medial to lateral approach, staying at the level of the upper vertebral end plate will lead the surgeon to the tip of the TP. From that point, dissection can be carried out as described above. This study examined the anatomy of the TP and defined the approach to expose the VA safely during anterior cervical spine exposure. Clin. Anat. 30:492-497, 2017. © 2017 Wiley Periodicals, Inc.