Lipolysis inhibition improves the survival of fat grafts through ameliorating lipotoxicity and inflammation.

Fat grafting is a promising technique for correcting soft tissue abnormalities, but oil cyst formation and graft fibrosis frequently impede the therapeutic benefit of fat grafting. The lipolysis of released oil droplets after grafting may make the inflammation and fibrosis in the grafts worse; therefore, by regulating adipose triglyceride lipase (ATGL) via Atglistatin (ATG) and Forskolin (FSK), we investigated the impact of lipolysis on fat grafts in this study. After being removed from the mice and chopped into small pieces, the subcutaneous fat from wild-type C57BL/6J mice was placed in three different solutions for two hours: serum-free cell culture medium, culture medium+FSK (50 µM), and culture medium+ATG (100 µM). Following centrifugation to remove water and free oil droplets, 0.3 mL of the fat particles per mouse was subcutaneously injected into the back of mice. Additionally, the subcutaneous fat grafting area was immediately injected with PBS (control group), ATG (30 mg/kg), and FSK (15 mg/kg) following fat transplantation. Detailed cellular events after grafting were investigated by histological staining, real-time polymerase chain reaction, immunohistochemistry/immunofluorescent staining, and quantification. Two weeks after grafting, grafts treated with ATG showed lower expression of ATGL and decreased mRNA levels of TNFα and IL-6. In contrast, grafts treated with ATG showed elevated expression levels of IL-4 and IL-13 compared to the control grafts. In addition, fewer apoptotic cells and oil cysts were observed in ATG grafts. Meanwhile, a higher CD206+/CD68+ ratio of macrophages and more CD31+ vascular endothelial cells existed in the 2-month ATG grafts. In comparison to the control, ATG treatment improved the volume retention of grafts, and decreased graft fibrosis and oil cyst formation. By preventing oil droplet lipolysis, pharmacological suppression of ATGL shielded adipocytes from lipotoxicity following grafting. Additionally, ATG ameliorated the apoptosis and inflammation brought on by adipocyte death and oil droplet lipolysis in grafted fat. These all indicate that lipolysis inhibition improved transplanted fat survival and decreased the development of oil cysts and graft fibrosis, offering a potential postoperative pharmacological intervention for bettering fat grafting.

BRaf signaling principles unveiled by large-scale human mutation analysis with a rapid lentivirus-based gene replacement method.

Rapid advances in genetics are linking mutations on genes to diseases at an exponential rate, yet characterizing the gene-mutation-cell-behavior relationships essential for precision medicine remains a daunting task. More than 350 mutations on small GTPase BRaf are associated with various tumors, and ∼40 mutations are associated with the neurodevelopmental disorder cardio-facio-cutaneous syndrome (CFC). We developed a fast cost-effective lentivirus-based rapid gene replacement method to interrogate the physiopathology of BRaf and ∼50 disease-linked BRaf mutants, including all CFC-linked mutants. Analysis of simultaneous multiple patch-clamp recordings from 6068 pairs of rat neurons with validation in additional mouse and human neurons and multiple learning tests from 1486 rats identified BRaf as the key missing signaling effector in the common synaptic NMDA-R-CaMKII-SynGap-Ras-BRaf-MEK-ERK transduction cascade. Moreover, the analysis creates the original big data unveiling three general features of BRaf signaling. This study establishes the first efficient procedure that permits large-scale functional analysis of human disease-linked mutations essential for precision medicine.

MiR-155-5p Aggravated Astrocyte Activation and Glial Scarring in a Spinal Cord Injury Model by Inhibiting Ndfip1 Expression and PTEN Nuclear Translocation.

Central nervous injury and regeneration repair have always been a hot and difficult scientific questions in neuroscience, such as spinal cord injury (SCI) caused by a traffic accident, fall injury, and war. After SCI, astrocytes further migrate to the injured area and form dense glial scar through proliferation, which not only limits the infiltration of inflammatory cells but also affects axon regeneration. We aim to explore the effect and underlying mechanism of miR-155-5p overexpression promoted astrocyte activation and glial scarring in an SCI model. MiR-155-5p mimic (50 or 100 nm) was used to transfect CTX-TNA2 rat brain primary astrocyte cell line. MiR-155-5p antagonist and miR-155-5p agomir were performed to treat SCI rats. MiR-155-5p mimic dose-dependently promoted astrocyte proliferation, and inhibited cell apoptosis. MiR-155-5p overexpression inhibited nuclear PTEN expression by targeting Nedd4 family interacting protein 1 (Ndfip1). Ndfip1 overexpression reversed astrocyte activation which was induced by miR-155-5p mimic. Meanwhile, Ndfip1 overexpression abolished the inhibition effect of miR-155-5p mimic on PTEN nuclear translocation. In vivo, miR-155-5p silencing improved SCI rat locomotor function and promoted astrocyte activation and glial scar formation. And miR-155-5p overexpression showed the opposite results. MiR-155-5p aggravated astrocyte activation and glial scarring in a SCI model by targeting Ndfip1 expression and inhibiting PTEN nuclear translocation. These findings have ramifications for the development of miRNAs as SCI therapeutics.

High-Resolution Electron Tomography of Ultrathin Boerdijk-Coxeter-Bernal Nanowire Enabled by Superthin Metal Surface Coating.

The rapid advancement of transmission electron microscopy has resulted in revolutions in a variety of fields, including physics, chemistry, and materials science. With single-atom resolution, 3D information of each atom in nanoparticles is revealed, while 4D electron tomography is shown to capture the atomic structural kinetics in metal nanoparticles after phase transformation. Quantitative measurements of physical and chemical properties such as chemical coordination, defects, dislocation, and local strain have been made. However, due to the incompatibility of high dose rate with other ultrathin morphologies, such as nanowires, atomic electron tomography has been primarily limited to quasi-spherical nanoparticles. Herein, the 3D atomic structure of a complex core-shell nanowire composed of an ultrathin Boerdijk-Coxeter-Bernal (BCB) core nanowire and a noble metal thin layer shell deposited on the BCB nanowire surface is discovered. Furthermore, it is demonstrated that a new superthin noble metal layer deposition on an ultrathin BCB nanowire could mitigate electron beam damage using an in situ transmission electron microscope and atomic resolution electron tomography. The colloidal coating method developed for electron tomography can be broadly applied to protect the ultrathin nanomaterials from electron beam damage, benefiting both the advanced material characterizations and enabling fundamental in situ mechanistic studies.

FXR1 regulation of parvalbumin interneurons in the prefrontal cortex is critical for schizophrenia-like behaviors.

Parvalbumin interneurons (PVIs) are affected in many psychiatric disorders including schizophrenia (SCZ), however the mechanism remains unclear. FXR1, a high confident risk gene for SCZ, is indispensable but its role in the brain is largely unknown. We show that deleting FXR1 from PVIs of medial prefrontal cortex (mPFC) leads to reduced PVI excitability, impaired mPFC gamma oscillation, and SCZ-like behaviors. PVI-specific translational profiling reveals that FXR1 regulates the expression of Cacna1h/Cav3.2 a T-type calcium channel implicated in autism and epilepsy. Inhibition of Cav3.2 in PVIs of mPFC phenocopies whereas elevation of Cav3.2 in PVIs of mPFC rescues behavioral deficits resulted from FXR1 deficiency. Stimulation of PVIs using a gamma oscillation-enhancing light flicker rescues behavioral abnormalities caused by FXR1 deficiency in PVIs. This work unveils the function of a newly identified SCZ risk gene in SCZ-relevant neurons and identifies a therapeutic target and a potential noninvasive treatment for psychiatric disorders.

Comparison of percutaneous endoscopic and open posterior lumbar interbody fusion for the treatment of single-segmental lumbar degenerative diseases.

BACKGROUND: Endoscopic lumbar interbody fusion has become an emerging technique. Some researchers have reported the technique of percutaneous endoscopic transforaminal lumbar interbody fusion. We propose percutaneous endoscopic posterior lumbar interbody fusion (PE-PLIF) as an alternative approach. The purpose of this study was to assess the clinical efficacy of PE-PLIF by comparing percutaneous endoscopic and open posterior lumbar interbody fusion (PLIF). METHODS: Thirty patients were enrolled in each group. Demographic data, perioperative data, and radiological parameters were collected prospectively. The clinical outcomes were evaluated by visual analog scale (VAS) and Oswestry Disability Index (ODI) scores. RESULTS: The background data were comparable between the two groups. The mean operation time was longer in the PE-PLIF group. The PE-PLIF group showed benefits in less blood loss and shorter hospital stay. VAS and ODI scores significantly improved in both groups. However, the VAS score of low-back pain was lower in the PE-PLIF group. The satisfaction rate was 96.7% in both groups. The radiological outcomes were similar in both groups. In the PE-PLIF group, the fusion rate was 93.3%, and the cage subsidence rate was 6.7%; in the open PLIF group, the fusion and cage subsidence rates were 96.7% and 16.7%. There were minor complications in one patient in the PE-PLIF group and two in the open PLIF group. CONCLUSIONS: The current study revealed that PE-PLIF is safe and effective compared with open PLIF. In addition, this minimally invasive technique may enhance postoperative recovery by reducing tissue damage and blood loss.

Secondary Metabolites and Their Cytotoxic Activity of Artemisia nitrosa Weber. and Artemisia marschalliana Spreng.

As a promising source of biologically active substances, the Artemisia species from Kazakhstan have not been investigated efficiently. Considering the rich history, medicinal values, and availability of the Artemisia plants, systematic investigations of two Artemisia species growing in the East Kazakhstan region were conducted. In this study, one new germacrane-type sesquiterpene lactone (11), together with 10 known sesquiterpenes and its dimer, were characterized from A. nitrosa Weber. Additionally, one new chromene derivative (1') with another 12 known compounds, including coumarins, sesquiterpene diketones, phenyl propanoids, polyacetylenics, dihydroxycinnamic acid derivatives, fatty acids, naphthalene derivatives, flavones, and caffeic acid derivatives were isolated from A. marschalliana Spreng. All compounds were isolated and identified for the first time from these two Artemisia species. The structures of new compounds (11, 1') were established by using UV, TOFMS, LC-MS, 1D and 2D NMR spectroscopic analyses. The cytotoxicity of all isolated compounds was evaluated. As a result, all compounds did not show significant inhibition against HL-60 and A-549 cell lines. The sesquiterpenoids isolated from A. nitrosa were tested for their inhibitory activity against the LPS-induced NO release from the RAW624.7 cells, and neither of them exhibited significant activity.

Preoperative Short-term High-Carbohydrate Diet Provides More High-Quality Transplantable Fat and Improves the Outcome of Fat Grafts in Mice.

BACKGROUND: Patients with a low BMI may have inadequate high-quality adipose tissue for transplantation. The influence of high-energy diets on adipose tissue and graft retention remains unknown. OBJECTIVES: The authors explored inguinal fat pad alternation in mice fed on a short-time high-fat diet (HFD) or a high-carbohydrate diet (HCD) preoperatively and the morphological and histological differences after transplantation. METHODS: Mice were fed HFD (60% kcal from fat, 20% from carbohydrate), HCD (9.3% kcal from fat, 80.1% from carbohydrate), or normal (12% kcal from fat, 67% kcal from carbohydrate) diets for 2 or 4 weeks. Histological analyses were carried out following hematoxylin and eosin staining as well as CD34 and proliferating cell nuclear antigen immunostaining. The uncoupling protein-1 expression was determined by western blotting. Fat pads from each group were grafted into the dorsal region of the recipient mice, and morphological and histological changes were determined 4, 8, and 12 weeks posttransplantation. Vascular endothelial growth factor-α and platelet-derived growth factor-α expression were determined using quantitative polymerase chain reaction. RESULTS: The inguinal fat pad volume increased in the HFD and HCD groups. The presence of multilocular adipocytes in inguinal fat of HCD-fed mice, combined with the increased uncoupling protein-1 content, suggested adipocyte browning. HCD grafts showed higher volume retention and reduced oil cyst formation, possibly attributed to better angiogenesis and adipogenesis. CONCLUSIONS: HCD enlarged adipose tissue and improved graft survival rates, which may be due to the browning of fat before grafting and enhanced angiogenesis after grafting.

An Astrocytic Influence on Impaired Tonic Inhibition in Hippocampal CA1 Pyramidal Neurons in a Mouse Model of Rett Syndrome.

Rett syndrome (RTT) is a severe neurodevelopmental disease caused by mutations in the methyl-CpG binding protein 2 (MECP2) gene. Although altered interneuron development and function are clearly demonstrated in RTT mice, a particular mode of inhibition, tonic inhibition, has not been carefully examined. We report here that tonic inhibition is significantly reduced in pyramidal neurons in the CA1 region of the hippocampus in mice where Mecp2 is deleted either in all cells or specifically in astrocytes. Since no change is detected in the level of GABA receptors, such a reduction in tonic inhibition is likely a result of decreased ambient GABA level in the extracellular space. Consistent with this explanation, we observed increased expression of a GABA transporter, GABA transporter 3 (GAT3), in the hippocampus of the Mecp2 KO mice, as well as a corresponding increase of GAT3 current in hippocampal astrocytes. These phenotypes are relevant to RTT because pharmacological blockage of GAT3 can normalize tonic inhibition and intrinsic excitability in CA1 pyramidal neurons, and rescue the phenotype of increased network excitability in acute hippocampal slices from the Mecp2 KO mice. Finally, chronic administration of a GAT3 antagonist improved a composite symptom score and extended lifespan in the Mecp2 KO mice. Only male mice were used in this study. These results not only advance our understanding of RTT etiology by defining a new neuronal phenotype and revealing how it can be influenced by astrocytic alterations, but also reveal potential targets for intervention.SIGNIFICANCE STATEMENT Our study reports a novel phenotype of reduced tonic inhibition in hippocampal CA1 pyramidal neurons in the Rett syndrome mice, reveal a potential mechanism of increased GABA transporter expression/activity in the neighboring astrocytes, describe a disease-relevant consequence in hyperexcitability, and provide preliminary evidence that targeting this phenotype may slow down disease progression in Rett syndrome mice. These results help our understanding of the disease etiology and identify a new therapeutic target for treating Rett syndrome.

Macrocephatriolides A and B: Two Guaianolide Trimers from Ainsliaea macrocephala as PTP1B Inhibitors and Insulin Sensitizers.

Macrocephatriolides A and B (1 and 2), two novel guaiane-type sesquiterpene lactone trimers possessing unique linkage patterns, were identified from the whole plant of Ainsliaea macrocephala. The trimeric architecture of 1 features a cyclohexene linkage and a methylene bridge, which were presumably constructed from three constitutive monomers via a Diels-Alder cycloaddition and a Michael addition, respectively. The three monomers of 2 were tethered by a 1,2-ethanediyl and a methylene linkage at the same time. Their complex structures were established by extensive analysis of spectroscopic data inclusive of band-selective CT-HSQC and CT-HMBC and time-dependent density functional theory (TDDFT) ECD calculations. Compound 2 showed potent inhibition against protein tyrosine phosphatase 1B (PTP1B) with an IC50 value of 26.26 ± 0.88 µM but not compound 1. In the kinetic study, compound 2 was disclosed as a competitive inhibitor of PTP1B with a Ki value of 16.34 ± 4.72 µM. In insulin-stimulated C2C12 myotubes, compound 2 dose-dependently enhanced glucose uptake by activating the insulin signaling pathway. Compound 2 might represent a new scaffold of insulin sensitizers.

Anti-inflammatory Eudesmane Sesquiterpenoids from Artemisia hedinii.

Fourteen new eudesmane sesquiterpenoids (1, 3-5, 7-16) and seven known analogues were isolated from the whole plant of Artemisia hedinii. Their structures were elucidated by spectroscopic data analysis and comparison with published NMR data, and their absolute configurations were confirmed by X-ray diffraction experiments and TDDFT ECD calculation. Compounds 1-15 were identified as eudesmane acids, which represent a kind of lactone ring-opening eudesmane-type sesquiterpenes with an acetoxyl or a hydroxy group attached to C-9. Compounds 1 and 2, 5 and 6, and 7 and 8 are three pairs of epimers isomerized at C-3, C-5, and C-11, respectively. Compounds 1-9, 11-13, 15-19, and 21 could influence the proinflammatory phenotype of the M1 macrophage. Among them, compounds 5, 8, 9, 12, 16, and 19 consistently exhibited anti-inflammatory effects, as evidenced by downregulating classic pro-inflammatory cytokines TNF-α, IL-12, IL-6, and IFN-γ in LPS-induced primary bone marrow derived M1 macrophages.

Percutaneous endoscopic posterior lumbar interbody fusion for the treatment of degenerative lumbar diseases: a technical note and summary of the initial clinical outcomes.

BACKGROUND: Percutaneous endoscopic lumbar interbody fusion was a new technique that leads to improved visualization, improved safety and less trauma than does the traditional procedure. The purpose of this study was to introduce the technique of percutaneous endoscopic posterior lumbar interbody fusion (PE-PLIF) and determine its efficacy. METHODS: 35 patients with an average age of 52.3±13.7 years were treated with single-segment PE-PLIF. The perioperative parameters and the radiographic parameters were measured. The visual analog scale (VAS) score for low back pain, VAS score for leg pain and Oswestry disability index (ODI) score were used to assess the levels of pain and function. RESULTS: The mean estimated volume of blood loss was 68.6±32.3 ml, operative time was 179.6±31.0 minutes. PE-PLIF significantly reduced the VAS score for low back pain, VAS score for leg pain and ODI score, and improved the posterior disc height, lumbar lordosis angle and segmental lordosis angle (p < 0.05). The rate of satisfaction was 94.3%. One patient suffered a dural tear. There was one case of contralateral radiculopathy that was relieved after conservative treatment. CONCLUSIONS: This research suggests that PE-PLIF is a minimally invasive, safe, and effective treatment for degenerative lumbar diseases requiring interbody fusion.

Fishing of α-Glucosidase's Ligands from Aloe vera by α-Glucosidase Functionalized Magnetic Nanoparticles.

α-Glucosidase was immobilized on magnetic nanoparticles (MNPs) for selective solid-phase extraction of the enzyme's ligands present in Aloe vera, which is a medicinal plant used for the treatment of various diseases and possesses anti-diabetic activity. One new compound, aloeacone (2), together with two known compounds, aloenin aglycone (1) and aloin A (3), were fished out as the enzyme's ligands. The structure of 2 was determined by HR-MS and comprehensive NMR techniques. Compound 3 exhibited a weak inhibitory effect on α-glucosidase, while compounds 1 and 2 were found to possess activation effects on the enzyme for the first time. It is interesting that both an inhibitor and agonists of α-glucosidase were fished out in one experiment.

Identification and Characterization of Glucosyltransferase That Forms 1-Galloyl-ß-d-Glucogallin in Canarium album L., a Functional Fruit Rich in Hydrolysable Tannins.

Hydrolysable tannins (HTs) are useful secondary metabolites that are responsible for pharmacological activities and astringent taste, flavor, and quality in fruits. They are also the main polyphenols in Canarium album L. (Chinese olive) fruit, an interesting and functional fruit that has been cultivated for over 2000 years. The HT content of C. album fruit was 2.3-13 times higher than that of berries with a higher content of HT. 1-galloyl-ß-d-glucose (ßG) is the first intermediate and the key metabolite in the HT biosynthesis pathway. It is catalyzed by UDP-glucosyltransferases (UGTs), which are responsible for the glycosylation of gallic acid (GA) to form ßG. Here, we first reported 140 UGTs in C. album. Phylogenetic analysis clustered them into 14 phylogenetic groups (A, B, D-M, P, and Q), which are different from the 14 typical major groups (A~N) of Arabidopsis thaliana. Expression pattern and correlation analysis showed that UGT84A77 (Isoform0117852) was highly expressed and had a positive correlation with GA and ßG content. Prokaryotic expression showed that UGT84A77 could catalyze GA to form ßG. These results provide a theoretical basis on UGTs in C. album, which will be helpful for further functional research and availability on HTs and polyphenols.

Profiling the influence of physicochemical parameters on the microbial community and flavor substances of zaopei.

BACKGROUND: Strong-flavor baijiu is a traditional distilled alcoholic beverage with a long history in China. The fermented grains play a pivotal role in the production of baijiu. The purpose of this study was to evaluate and compare the microbiota and flavor substances present in fermented zaopei (ZP) from pits of different ages. High-throughput sequencing, headspace solid-phase microextraction gas chromatography-mass spectrometry, principal component analysis, community composition analysis, and redundancy analysis were used to analyze and evaluate the impact of environmental factors on microbial communities and flavor substances. RESULTS: Six genera of bacteria (e.g., Caproiciproducens, Syntrophaceticus, Sedimentibacter, Hydrogenispora, Pelotomaculum and Bacillus) and seven genera of fungi (Cladosporium, Debaryomyces, Dipodascus, Auxarthron, Cephalotrichum, unclassified Stachybotryaceae, unclassified Microascaceae and Cephalotrichum) notably affected the production of hexanoic acid (an important flavor compound). Moisture and alcohol content also had considerable effects on the production of the flavor compounds such as ethyl lactate, hexanoic acid, and ethyl hexanoate. The profiles of volatile compounds present in ZP were different between the aged and new pits; these profiles were mainly reflected in the concentration and types of alcohols, aldehydes, esters, and aromatic compounds. CONCLUSIONS: This paper provides a comprehensive overview of the physicochemical parameters, flavor substances, and microbial population distribution of ZP. Characterization of various ZP samples help to elucidate the fermentation mechanisms and offer a theoretical reference to control and enhance the quality of Baijiu. © 2021 Society of Chemical Industry.

Sesquiterpene lactone dimers from Artemisia lavandulifolia inhibit interleukin-1ß production in macrophages through activating autophagy.

Twelve new sesquiterpene lactone dimers, lavandiolides A-L (1-12), were isolated from the whole plants of Artemisia lavandulifolia. Among them, compounds 1-6 are 1,3-linked Diels-Alder adducts between two guaianolide monomers, and 7-12 are 2,4-linked sesquiterpene lactone dimers. Their structures were elucidated by comprehensive analysis of HRESIMS, 1D and 2D NMR spectra. Their absolute configurations were determined by ECD spectra and single-crystal X-ray diffraction analyses with Cu Kα radiation. The nitric oxide (NO) inhibitory effect of all the isolates was assessed on lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. Compounds 1, 3, 7 and 9 showed potent inhibitory effects on NO production, with IC50 values of 0.61 ± 0.15, 1.64 ± 0.04, 1.89 ± 0.16, and 1.40 ± 0.23 µM, respectively. Furthermore, compound 1 inhibited NLRP3 (NOD-, LRR- and pyrin domain-containing protein 3) inflammasome-mediated interleukin-1ß (IL-1ß) production through activating autophagy.

Anti-SARS-CoV-2 activities in vitro of Shuanghuanglian preparations and bioactive ingredients.

Human infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19) and there is no cure currently. The 3CL protease (3CLpro) is a highly conserved protease which is indispensable for CoVs replication, and is a promising target for development of broad-spectrum antiviral drugs. In this study we investigated the anti-SARS-CoV-2 potential of Shuanghuanglian preparation, a Chinese traditional patent medicine with a long history for treating respiratory tract infection in China. We showed that either the oral liquid of Shuanghuanglian, the lyophilized powder of Shuanghuanglian for injection or their bioactive components dose-dependently inhibited SARS-CoV-2 3CLpro as well as the replication of SARS-CoV-2 in Vero E6 cells. Baicalin and baicalein, two ingredients of Shuanghuanglian, were characterized as the first noncovalent, nonpeptidomimetic inhibitors of SARS-CoV-2 3CLpro and exhibited potent antiviral activities in a cell-based system. Remarkably, the binding mode of baicalein with SARS-CoV-2 3CLpro determined by X-ray protein crystallography was distinctly different from those of known 3CLpro inhibitors. Baicalein was productively ensconced in the core of the substrate-binding pocket by interacting with two catalytic residues, the crucial S1/S2 subsites and the oxyanion loop, acting as a "shield" in front of the catalytic dyad to effectively prevent substrate access to the catalytic dyad within the active site. Overall, this study provides an example for exploring the in vitro potency of Chinese traditional patent medicines and effectively identifying bioactive ingredients toward a specific target, and gains evidence supporting the in vivo studies of Shuanghuanglian oral liquid as well as two natural products for COVID-19 treatment.

Accurate identification of myocardial viability after myocardial infarction with novel manganese chelate-based MR imaging.

We developed a novel manganese (Mn2+ ) chelate for magnetic resonance imaging (MRI) assessment of myocardial viability in acute and chronic myocardial infarct (MI) models, and compared it with Gadolinium-based delay enhancement MRI (Gd3+ -DEMRI) and histology. MI was induced in 14 rabbits by permanent occlusion of the left circumflex coronary artery. Gd3+ -DEMRI and Mn2+ chelate-based delayed enhancement MRI (Mn2+ chelate-DEMRI) were performed at 7 days (acute MI, n = 8) or 8 weeks (chronic MI, n = 6) after surgery with sequential injection of 0.15 mmol/kg Gd3+ and Mn2+ chelate. The biodistribution of Mn2+ in tissues and blood was measured at 1.5 and 24 h. Blood pressure, heart rate (HR), left ventricular (LV) function, and infarct fraction (IF) were analyzed, and IF was compared with the histology. The Mn2+ chelate group maintained a stable hemodynamic status during experiment. For acute and chronic MI, all rabbits survived without significant differences in HR or LV function before and after injection of Mn2+ chelate or Gd3+ (p > 0.05). Mn2+ chelate mainly accumulated in the kidney, liver, spleen, and heart at 1.5 h, with low tissue uptake and urine residue at 24 h after injection. In the acute MI group, there was no significant difference in IF between Mn2+ chelate-DEMRI and histology (22.92 ± 2.21% vs. 21.79 ± 2.25%, respectively, p = 0.87), while Gd3+ -DEMRI overestimated IF, as compared with histology (24.54 ± 1.73%, p = 0.04). In the chronic MI group, there was no significant difference in IF between the Mn2+ chelate-DEMRI, Gd3+ -DEMRI, and histology (29.50 ± 11.39%, 29.95 ± 9.40%, and 29.00 ± 10.44%, respectively, p > 0.05), and all three were well correlated (r = 0.92-0.96, p < 0.01). We conclude that the use of Mn2+ chelate-DEMRI is reliable for MI visualization and identifies acute MI more accurately than Gd3+ -DEMRI.

Regulation of neural differentiation, synaptic scaling and animal behavior by MeCP2 phophorylation.

Highly expressed in the mammalian brain and widely distributed across the genome, MeCP2 is a key player in recognizing modified DNA and interpreting the epigenetic information encoded in different DNA methylation/hydroxymethylation patterns. Alterations in sequence or copy number of the X-linked human MECP2 gene cause either Rett syndrome (RTT) or MECP2 duplication syndrome. Alterations in MECP2 levels have also been identified in patients with autism. To fully understand the significant role of MECP2 in regulating the development and function of the nervous system, it is important to study all aspects of MeCP2 function. Stimulus-induced MeCP2 phosphorylation has been shown to influence the proliferation and differentiation of neural progenitor cells, synaptic scaling, excitatory synaptogenesis, and animal behavior. However, all of the previous functional evidence is from studying phospho-dead mutations. In addition, the relationship between phosphorylation events at multiple sites on the MeCP2 protein is not well understood. Here, we report the generation of a phospho-mimic knockin Mecp2 mouse line. At the synaptic and behavioral levels, the phospho-mimic Mecp2 mice show phenotypes opposite to those observed in phospho-dead mutation at the same phosphorylation site. Moreover, we report opposite phenotypes between phospho-mutants of two sites on the MeCP2 protein. Our new data further confirm the functional significance of specific MeCP2 phosphorylation event and support the opposing regulatory role between different MeCP2 phosphorylation events.