Miracle-dz/UniFAR-FTUs huggingface dataset:
Effect of repeated, long term capsaicin ingestion on intestinal chemo‐ and mechanosensation in healthy volunteers

Abstract Repeated ingestion of capsaicin over a prolonged period reduces symptoms in functional dyspepsia, but initially induces upper abdominal symptoms. Sensitizing chemonociception might be the cause for this initial effect of capsaicin. The aim was to evaluate the effect of prolonged capsaicin ingestion on duodenal chemo‐ and mechanonociception. Healthy subjects ingested capsules containing either 0.25 mg capsaicin tid (n = 8) or placebo (n = 8) for 28 days. Before (day 0) and after (day 29) capsule ingestion the duodenum was distended with a balloon and perfused with a capsaicin solution. Mechanically and chemically induced sensation was evaluated by a graded questionnaire. Aggregate perception scores were calculated. Perception scores during balloon distensions with 12 and 18 mmHg were significantly lower after 4 weeks capsaicin when compared to baseline (P < 0.05). Balloon volumes to induce first sensation (63 ± 14 mL (day 0) vs 92 ± 22 mL (day 29); P < 0.05) and discomfort (101 ± 12 mL vs 137 ± 22 mL; P = 0.05) where significantly higher after 4 weeks capsaicin application; balloon pressures to induce sensations were not significantly different. Intraluminal capsaicin application induced first sensation after 3.4 ± 1.5 min (day 0) and 7.5 ± 4.6 min (day 29) (P < 0.05) and discomfort after 15.9 ± 9.8 min and 22.4 ± 7.3 min (P < 0.05). The quality of perception was not altered by repeated capsaicin ingestion. In the placebo group, mechano‐ and chemonociception remained unaltered at day 29. Four weeks ingestion of capsaicin desensitized both chemonociceptive and mechanonociceptive pathways in healthy volunteers. Symptom reduction after prolonged treatment with capsaicin in dyspeptic patients might be attributed to a dual desensitizing effect of capsaicin on chemonociceptors and mechanonociceptors.
Deimination of linker histones links neutrophil extracellular trap release with autoantibodies in systemic autoimmunity

Autoantibodies to nuclear antigens arise in human autoimmune diseases, but a unifying pathogenetic mechanism remains elusive. Recently we reported that exposure of neutrophils to inflammatory conditions induces the citrullination of core histones by peptidylarginine deiminase 4 (PAD4) and that patients with autoimmune disorders produce autoantibodies that recognize such citrullinated histones. Here we identify histone H1 as an additional substrate of PAD4, localize H1 within neutrophil extracellular traps, and detect autoantibodies to citrullinated H1 in 6% of sera from patients with systemic lupus erythematosus and Sjögren's syndrome. No preference for deiminated H1 was observed in healthy control sera and sera from patients with scleroderma or rheumatoid arthritis. We map binding to the winged helix of H1 and determine that citrulline 53 represents a key determinant of the autoantibody epitope. In addition, we quantitate RNA for H1 histone subtypes in mature human neutrophils and identify citrulline residues by liquid chromatography and tandem mass spectrometry. Our results indicate that deimination of linker histones generates new autoantibody epitopes with enhanced potential for stimulating autoreactive human B cells. —Dwivedi, N. , Neeli, I. , Schall, N. , Wan, H. , Desiderio, D. M. , Csernok, E. , Thompson, P. R. , Dali, H. , Briand, J.‐P., Muller, S. , Radic, M. Deimination of linker histones links neutrophil extracellular trap release with autoantibodies in systemic autoimmunity. FASEB J. 28, 2840–2851 (2014). www.fasebj. org
Does magnetic stimulation of sacral nerve roots modify colonic motility? Results of a randomized double‐blind sham‐controlled study

Abstract Although sacral nerve root stimulation (SNS) can result in a symptomatic improvement of faecal incontinence, the mechanism of action remains unknown. The aim of this study was to assess whether short‐term magnetic SNS can inhibit pharmacologically induced propulsive colonic contractions. Twelve healthy volunteers (median age: 43.5 years old) were studied on two separate occasions and randomized into either active (15 Hz, 100% output intensity for 5 s min−1 for 30 min) or sham rapid rate lumbosacral magnetic stimulation (rLSMS). Colorectal motility was recorded with a manometric catheter located at the most proximal transducer in the left colon and the most distal, in the rectum. Colonic contractions were provoked by instilling Bisacodyl. The effects of rLSMS on colonic, sigmoid and rectal contractions were monitored and recorded after Bisacodyl instillation. The appearance of high‐amplitude contractions propagated or not (HAC/HAPC) provoked by Bisacodyl instillation was significantly delayed during active compared to sham stimulation (P = 0.03). There was no difference in the characteristics of HAC/HAPC (i.e. frequency, amplitude, duration, velocity of propagation) or the motility index with active or sham stimulation. The perception of urgency tended to be decreased with rLSMS following Bisacodyl instillation. The catheter was expulsed within a median of 16.5 min (range 8–39) after Bisacodyl administration during active stimulation compared to 14 min (range 5–40) during sham stimulation (P = 0.03). This study suggests that rLSMS could delay the appearance of the first Bisacodyl‐induced colonic contractions.
Hole trapping of G-quartets in a G-quadruplex.

Since reduction and oxidation of DNA are essential processes occurring in various biological phenomena, electron and hole transfer in DNA has drawn recent attention because of its importance and potential application in biological science and nano-biotechnology, respectively. In practice, it is known that the reduction of DNA closely relates to the repair of damaged DNA such as a T-T cyclobutane lesion, whereas the oxidation of DNA promotes oxidative damage, apoptosis, and cancer. Thus, it is important to understand the mechanisms and dynamics of DNA-mediated charge-transfer processes. Excess electron transfer (EET) in DNA has been studied by various techniques, such as laser flash photolysis, g-ray radiolysis, or product analysis which were used to analyze the cleavage of 5-bromo-2’-deoxyuridine (BrdU) or the T-T dimer in DNA by photoinduced electron transfer. The laser flash photolysis is conducted principally on shortlength DNA, which is containing four A-T base pairs between two chromophores. Meanwhile, the DNA-mediated hole transfer occurs over a distance greater than 20 nm and the migration of the hole along the DNA involves many steps of short-distance charge-transfer processes between stacked guanine (G) bases because guanine among the four natural DNA bases is most sensitive to oxidation. The hole transfer rate depends on the inserted nucleobase between the G-C base pairs. In addition, the delocalization of the charge over the stacked G bases along the DNA stem has also been reported. Most studies on DNA-mediated charge-transfer processes have been performed on a DNA duplex with Watson–Crick base pairing. However, recently, non-B DNAs including Gquadruplexes have attracted great attention as fascinating materials for nanotechnology because of their unique structures. Especially, G-quadruplexes formed from various G-rich sequences have received great attention in biological research because in vitro they block the binding of telomerase and act as a transcriptional repressor element and enzyme to provide cancerous cells immortality. Furthermore, G-quadruplexes are an emerging topic for developing DNA-based molecular electronic devices because of their ability as electron carrier, their unique hole-trapping property, and their high conductance. With hole transfer in DNA, recently, hole trapping has also been regarded as an important process to determine the overall efficiency of hole migration in DNA. Here, we have investigated the hole transfer and trapping in a riboflavin-labeled G-quadruplex using femtosecond (fs) laser flash photolysis and pulse radiolysis. In contrast to duplex DNAs, in which p-p stacking has been believed to be a medium for hole transfer, G-quadruplexes have G-quartet structures composed of four G-bases located in the same plane and have also the stacked G-bases (Scheme 1). Thus, it
MR-1 Modulates Proliferation and Migration of Human Hepatoma HepG2 Cells through Myosin Light Chains-2 (MLC2)/Focal Adhesion Kinase (FAK)/Akt Signaling Pathway*

The key of cell migration process on solid substrates is phosphorylation of myosin light chain-2 (MLC2), which is implicated in a variety of intracellular functions. The previous data show that MLC2 interacts with a novel human gene, myofibrillogenesis regulator 1 (MR-1). Here, we reported that MR-1 was specially overexpressed in human hepatoma HepG2 cells. Transient treatment of cells with small interfering RNA (siRNA) against MR-1 or stable transfection of cells with plasmid expressing MR-1-siRNA led to inhibitions of cell proliferation, migration, and adhesion. Following down-regulation of MR-1, the phosphorylations of MLC2, focal adhesion kinase (FAK), and Akt were dramatically decreased, and the formation of stress fiber was destroyed by MR-1-siRNAs in hepatoma HepG2 cells. In addition, exogenous MR-1-induced as well as inherent phosphorylations of FAK and Akt were decreased by MLC kinase (MLCK) inhibitor, and F-actin polymerization inhibitor also decreased phosphorylations of FAK and Akt. Correspondingly, MR-1-enhanced migration of cells was also inhibited by these two inhibitors. These indicated that MLC2 activation and intact actin cytoskeleton were pivotal for MR-1 function. In vivo data showed that MR-1-siRNA markedly inhibited growth of human HepG2. This study suggested that overexpression of MR-1 was associated with cancer cell proliferation and migration through MLC2 and that MR-1 might be a potential cancer therapeutic target.
Glucocorticoids increase adipocytes in muscle by affecting IL‐4 regulated FAP activity

An increase in intramuscular adipocyte tissue (IMAT) is associated with glucose dysregulation, decreased muscle strength, and increased risk of disability. Unfortunately, the mechanisms stimulating intramuscular adipogenesis remain unclear. We found that dexamethasone (Dex) administration to mice with injured muscles stimulates the accumulation of IMAT. To identify precursors of these adipocytes, we isolated satellite cells and fibro/adipogenic progenitors (FAPs) from muscle; satellite cells did not differentiate into adipocytes even following Dex treatment. In contrast, Dex stimulated FAP differentiation into adipocytes. In vivo, we transplanted purified FAPs from transgenic, EGFP mice into the injured muscles of C57/BL6 mice and found that Dex administration stimulated adipogenesis from FAP‐EGFP. The increase in adipogenesis depended on Dex‐induced inhibition of interleukin‐4 (IL‐4). In the injured muscle of IL‐4‐knockout mice, the levels of adipocytes were increased, while in the injured muscles of Dex‐treated mice with IL‐4 injections, adipogenesis was suppressed. In cultured FAPs, IL‐4 inhibited Dex‐induced conversion of FAPs into adipocytes; this did not occur in FAPs expressing knockdown of the IL‐4 receptor. Thus, we concluded that glucocorticoids stimulate FAPs to differentiate into adipocytes in injured muscles. This process is blocked by IL‐4, suggesting that interfering with IL‐4 signaling could prevent adipogenesis in muscle. —Dong, Y. , Silva, K. A. S. , Dong, Y. , Zhang, L. Glucocorticoids increase adipocytes in muscle by affecting IL‐4 regulated FAP activity. FASEB J. 28, 4123‐4132 (2014). www.fasebj. org
Differential Regulation of STAT Family Members by Glycogen Synthase Kinase-3*

Excessive neuroinflammation contributes to many neurological disorders and is poorly controlled therapeutically. The signal transducer and activator of transcription (STAT) family of transcription factors has a central role in inflammatory reactions, being stimulated by multiple cytokines and interferons and regulating the expression of many proteins involved in inflammation. We found that STAT3 activation is highly dependent on glycogen synthase kinase-3 (GSK3). Inhibitors of GSK3 greatly reduced (>75%) the activating STAT3 tyrosine phosphorylation in mouse primary astrocytes, microglia, and macrophage-derived RAW264.7 cells induced by interferon-γ (IFNγ), IFNα, interleukin-6, or insulin. GSK3 inhibitors blocked STAT3 DNA binding activity and the expression of STAT3-induced GFAP and Bcl-3. GSK3 dependence was selective for activation of STAT3 and STAT5, whereas STAT1 and STAT6 activation were GSK3-independent. Knockdown of the two GSK3 isoforms showed STAT3 and STAT5 activation were dependent on GSK3β, but not GSK3α. The regulatory mechanism involved GSK3β binding STAT3 and promoting its association with the IFNγ receptor-associated intracellular signaling complex responsible for activating STAT3. Furthermore, GSK3β associated with the IFNγ receptor and was activated by stimulation with IFNγ. Thus, inhibitors of GSK3 reduce the activation of STAT3 and STAT5, providing a mechanism to differentially regulate STATs to modulate the inflammatory response.
Intrauterine growth restriction disrupts developmental epigenetics around distal growth hormone response elements on the rat hepatic IGF‐1 gene

Intrauterine growth restriction (IUGR) decreases serum IGF‐1 levels. Postnatal IGF‐1 expression is transcriptionally regulated by growth hormone (GH) through growth hormone response elements (GHREs). We hypothesized that IUGR disrupts the normal developmental maturation of hepatic IGF‐1 intron 2 growth hormone response element (IN2GHRE) histone methylation of key lysines and DNA methylation. We also evaluated a 5‘ distal weak enhancer (IGF‐15‘‐upstream region growth hormone response element; 5URGHRE) as a GHRE specificity control. IUGR was induced through a well‐characterized model of bilateral uterine artery ligation of the pregnant rat. Offspring livers were tested at d 0 and 21. Chromatin immunoprecipitation and bisulfite sequencing quantified epigenetic characteristics. We found that distinct age‐related developmental patterns of histone and DNA methylation characterize each GHRE. Development increased H3K4 trimethylation (me3) in both GHREs. However, H3K9me3 decreased with age at IN2GHRE and increased with age at 5URGHRE. IUGR altered the developmental pattern of H3K4me3 and K9me3 around the GHREs in a sex‐specific manner at d 21. Developmental and IUGR‐induced DNA methylation occurred in a GHRE‐, CpG site‐, and sex‐specific manner. We conclude that IUGR disrupts developmental epigenetics around distal GHREs on the rat hepatic IGF‐1 gene. —Fu, Q. , McKnight, R. A. , Callaway, C. W. , Yu, X. , Lane, R. H. , Majnik, A. V. Intrauterine growth restriction disrupts developmental epigenetics around distal growth hormone response elements on the rat hepatic IGF‐1 gene. FASEB J. 29, 1176‐1184 (2015). www.fasebj. org
Crystal Structure of HAb18G/CD147

CD147, a member of the immunoglobulin superfamily (IgSF), plays fundamental roles in intercellular interactions in numerous pathological and physiological processes. Importantly, our previous studies have demonstrated that HAb18G/CD147 is a novel hepatocellular carcinoma (HCC)-associated antigen, and HAb18G/CD147 stimulates adjacent fibroblasts and HCC cells to produce elevated levels of several matrix metalloproteinases, facilitating invasion and metastasis of HCC cells. In addition, HAb18G/CD147 has also been shown to be a novel universal cancer biomarker for diagnosis and prognostic assessment of a wide range of cancers. However, the structural basis underlying the multifunctional character of CD147 remains unresolved. We report here the crystal structure of the extracellular portion of HAb18G/CD147 at 2.8Å resolution. The structure comprises an N-terminal IgC2 domain and a C-terminal IgI domain, which are connected by a 5-residue flexible linker. This unique C2-I domain organization is distinct from those of other IgSF members. Four homophilic dimers exist in the crystal and adopt C2-C2 and C2-I dimerization rather than V-V dimerization commonly found in other IgSF members. This type of homophilic association thus presents a novel model for homophilic interaction between C2 domains of IgSF members. Moreover, the crystal structure of HAb18G/CD147 provides a good structural explanation for the established multifunction of CD147 mediated by homo/hetero-oligomerizations and should represent a general architecture of other CD147 family members.
Aldosterone synthase knockout mouse as a model for sodium‐induced endothelial sodium channel up‐regulation in vascular endothelium

Recently, a novel feedforward activation of the endothelial epithelial sodium channel (ENaC) [endothelial sodium channel (EnNaC)] by sodium was reported that counteracts ENaC function in kidney. In the absence of aldosterone, a rise in extracellular sodium (>145 mM) increases EnNaC surface abundance, thereby stiffening the cortex of vascular endothelial cells (ECs) in vitro. The latter reduces the release of NO—the hallmark of endothelial dysfunction. Here, we test whether high extracellular sodium per se increases EnNaC expression and cortical stiffness in an aldosterone synthase (Cyp11b2)‐deficient (AS‐/‐) mouse model. Therefore, we employed in situ ECs of ex vivo aorta preparations from wild‐type (WT) and AS‐/‐. EnNaC surface expression (‐16%) and cortical stiffness (‐22%) were reduced in AS‐/‐, compared with WT, whereas NO secretion was exclusively detectable in AS‐/‐. EnNaC inhibition with benzamil decreased stiffness in both, while mineralocorticoid receptor antagonism diminished stiffness only in the WT. In the absence of aldosterone, high sodium (150 mM) increased EnNaC surface expression ex vivo (plus 19%) and cortical stiffness ex vivo (plus 41%) and in vivo (plus 44%). Application of aldosterone adjusted the stiffness of AS‐/‐to the WT level. We conclude that high sodium per se determines EnNaC expression and consequently endothelial cortical nanomechanics, thus likely contributing to endothelial dysfunction. —Jeggle, P., Hofschröer, V. , Maase, M. , Bertog, M. , Kusche‐Vihrog, K. Aldosterone synthase knockout mouse as a model for sodium‐induced endothelial sodium channel up‐regulation in vascular endothelium. FASEB J. 30, 45‐53 (2016). www.fasebj. org
Pharmacological therapy for atrial fibrillation: current options and new agents

Atrial fibrillation is the most commonly encountered cardiac arrhythmia and is directly or indirectly responsible for considerable mortality, morbidity and health care burden. The available medical therapy is limited by marginal efficacy, end-organ toxicity, as well as the potential for undesired ventricular proarrhythmia. Elucidation of the potential mechanisms that underlie the development of atrial fibrillation may provide new targets for drugs that circumvent the problems associated with current medical options. This review focuses on the current and potential future pharmacological agents directed at rhythm control and maintenance of sinus rhythm.
Rett Syndrome-causing Mutations in Human MeCP2 Result in Diverse Structural Changes That Impact Folding and DNA Interactions*

Most cases of Rett syndrome (RTT) are caused by mutations in the methylated DNA-binding protein, MeCP2. Here, we have shown that frequent RTT-causing missense mutations (R106W, R133C, F155S, T158M) located in the methylated DNA-binding domain (MBD) of MeCP2 have profound and diverse effects on its structure, stability, and DNA-binding properties. Fluorescence spectroscopy, which reports on the single tryptophan in the MBD, indicated that this residue is strongly protected from the aqueous environment in the wild type but is more exposed in the R133C and F155S mutations. In the mutant proteins R133C, F155S, and T158M, the thermal stability of the domain was strongly reduced. Thermal stability of the wild-type protein was increased in the presence of unmethylated DNA and was further enhanced by DNA methylation. DNA-induced thermal stability was also seen, but to a lesser extent, in each of the mutant proteins. Circular dichroism (CD) of the MBD revealed differences in the secondary structure of the four mutants. Upon binding to methylated DNA, the wild type showed a subtle but reproducible increase in α-helical structure, whereas the F155S and R106W did not acquire secondary structure with DNA. Each of the mutant proteins studied is unique in terms of the properties of the MBD and the structural changes induced by DNA binding. For each mutation, we examined the extent to which the magnitude of these differences correlated with the severity of RTT patient symptoms.
Cleavage-mediated Activation of Chk1 during Apoptosis*

The Chk1 kinase is highly conserved from yeast to humans and is well known to function in the cell cycle checkpoint induced by genotoxic or replication stress. The activation of Chk1 is achieved by ATR-dependent phosphorylation with the aid of additional factors. Robust genotoxic insults induce apoptosis instead of the cell cycle checkpoint, and some of the components in the ATR-Chk1 pathway are cleaved by active caspases, although it has been unclear whether the attenuation of the ATR-Chk1 pathway has some role in apoptosis induction. Here we show that Chk1 is activated by caspase-dependent cleavage when the cells undergo apoptosis. Treatment of chicken DT40 cells with various genotoxic agents, UV light, etoposide, or camptothecin induced Chk1 cleavage, which was inhibited by a pan-caspase inhibitor, benzyloxycarbonyl-VAD-fluoromethyl ketone. The cleavage of Chk1 was similarly observed in human Jurkat cells treated with a non-genotoxic apoptosis inducer, staurosporine. We have determined the cleavage site(s), Asp-299 in chicken and Asp-299 and Asp-351 in human cells. We further show that a truncated form of human Chk1 mimicking the N-terminal cleavage fragment (residues 1–299) possesses strikingly elevated kinase activity. Moreover, the ectopic expression of Chk1-(1–299) in human U2OS cells induces abnormal nuclear morphology with localized chromatin condensation and phosphorylation of histone H2AX. These results suggest that Chk1 is activated by caspase-mediated cleavage during apoptosis and might be implicated in enhancing apoptotic reactions rather than attenuating the ATR-Chk1 pathway.
Gly-Ala Repeats Induce Position- and Substrate-specific Regulation of 26 S Proteasome-dependent Partial Processing*

Partial degradation or regulated ubiquitin proteasome-dependent processing by the 26 S proteasome has been demonstrated, but the underlying molecular mechanisms and the prevalence of this phenomenon remain obscure. Here we show that the Gly-Ala repeat (GAr) sequence of EBNA1 affects processing of substrates via the ubiquitin-dependent degradation pathway in a substrate- and position-specific fashion. GAr-mediated increase in stability of proteins targeted for degradation via the 26 S proteasome was associated with a fraction of the substrates being partially processed and the release of the free GAr. The GAr did not cause a problem for the proteolytic activity of the proteasome, and its fusion to the N terminus of p53 resulted in an increase in the rate of degradation of the entire chimera. Interestingly the GAr had little effect on the stability of EBNA1 protein itself, and targeting EBNA1 for 26 S proteasome-dependent degradation led to its complete degradation. Taken together, our data suggest a model in which the GAr prevents degradation or promotes endoproteolytic processing of substrates targeted for the 26 S proteasome by interfering with the initiation step of substrate unfolding. These results will help to further understand the underlying mechanisms for partial proteasome-dependent degradation.