Atomic insight into prion disorder: An intricate detail gained by 0.5 μs molecular dynamics simulation of preventive G127V and deleterious D178V mutation in prion protein

In this study we are looking into two contradicting mutations found in prion protein (PrP) viz G127V and D178V, that are reportedly protective and pathogenic, respectively. Despite significant advances in comprehension of the role of pathogenic mutations, the role of protective mutation in amyloid fold inhibition still lacks a substantial basis. To understand the structural basis of protective mutation, molecular dynamics simulation coupled with protein-protein docking and molecular mechanics/Poisson-Boltzmann surface area analysis was used to understand the instant structural variability brought about by these mutations alone and in combination on PrP and prion-prion complex. Atomic-scale investigations successfully revealed that the binding pattern of prion-prion varies differentially in protective and pathogenic mutations with secondary structure showing distinct contrasting patterns, which could supposedly be a critical factor for differential prion behavior in protective and pathogenic mutations. Considering the reported role of an amyloid fold in prion-prion binding, the contrasting pattern has given us a lead in comprehending the role of these mutations and has been used in this study to look for small molecules that can inhibit amyloid fold for prion-prion interaction in pathogenic mutant carrying PrP.     

Hepatocyte differentiation of human induced pluripotent stem cells is modulated by stearoyl‐CoA desaturase 1 activity

Stearoyl‐CoA desaturase 1 (SCD1) plays important roles in organ development, glucose tolerance, insulin sensitivity, and cancer. Here, we examined the role of SCD1 for the differentiation of human induced pluripotent stem (hiPS) cells to liver cells by using drug inhibition and biochemical experiments. hiPS cells cultured in a pro‐hepatic medium were exposed to an SCD1 inhibitor at various stages throughout differentiation. Liver‐specific markers, specifically α‐fetoprotein, albumin and urea in conditioned medium, and hepatocyte nuclear factor 4α (HNF4α) and cytochrome P450 7A1 (CYP7A1) gene expressions and triglyceride in cellular extracts were analyzed at various development stages. Measures of hepatocyte‐specific function and triglyceride accumulation in later stages were strongly inhibited a minimum of −29% (P < 0.05) by SCD1 inhibitor in the early stage of hepatic differentiation and effectively reversed (>30%, P < 0.01) by the addition of oleate. The results were also reproducible with human primary mononuclear cells (hPMN). SCD1 inhibitor had no significant effect on liver‐specific markers when it was added in the hepatic maturation stage. However, it strikingly led to higher albumin (1.6‐fold, P = 0.03) and urea (1.9‐fold, P = 0.02) production, and HNF4α (1.9‐fold, P = 0.02) and CYP7A1 (1.3‐fold, P = 0.03) expression upon incubation during the lineage‐commitment stage. Hepatic differentiation from cultured hiPS cells is sensitive to SCD1 inhibition and this sensitivity is affected by the stage of cellular differentiation. Notably, findings also indicate that this notion can be extended to hPMN. The requirement for SCD1 activity in functional differentiation of hepatocytes may have relevance for human liver disease and metabolic dysregulation.     

Effects of Self‐Conditioning Techniques (Self‐Hypnosis) in Promoting Weight Loss in Patients with Severe Obesity: A Randomized Controlled Trial

Objective

The usefulness of the rapid‐induction techniques of hypnosis as an adjunctive weight‐loss treatment has not been defined. This randomized controlled trial evaluated whether self‐conditioning techniques (self‐hypnosis) added to lifestyle interventions contributed to weight loss (primary outcome), changes in metabolic and inflammatory variables, and quality of life (QoL) improvement (secondary outcomes) in severe obesity.

Methods

Individuals (with BMI = 35‐50 kg/m²) without organic or psychiatric comorbidity were randomly assigned to the intervention (n = 60) or control arm (n = 60). All received exercise and behavioral recommendations and individualized diets. The intervention consisted of three hypnosis sessions, during which self‐hypnosis was taught to increase self‐control before eating. Diet, exercise, satiety, QoL, anthropometric measurements, and blood variables were collected and measured at enrollment and at 1 year (trial end).

Results

A similar weight loss was observed in the intervention (?6.5 kg) and control (?5.6 kg) arms (β = ?0.45; 95% CI: ?3.78 to 2.88; P = 0.79). However, habitual hypnosis users lost more weight (?9.6 kg; β = ?10.2; 95% CI: ?14.2 to ?6.18; P < 0.001) and greatly reduced their caloric intake (?682.5 kcal; β = ?643.6; 95% CI: ?1064.0 to ?223.2; P = 0.005) in linear regression models. At trial end, the intervention arm showed lower C‐reactive protein values (β = ?2.55; 95% CI: ?3.80 to ?1.31; P < 0.001), higher satiety (β = 19.2; 95% CI: 7.71‐30.6; P = 0.001), and better QoL (β = 0.09; 95% CI: 0.02‐0.16; P = 0.01).

Conclusions

Self‐hypnosis was not associated with differences in weight change but was associated with improved satiety, QoL, and inflammation. Indeed, habitual hypnosis users showed a greater weight loss.

     

Effects of Modafinil on Clonic Seizure Threshold Induced by Pentylenetetrazole in Mice: Involvement of Glutamate,Nitric oxide,GABA, and Serotonin Pathways

Epilepsy is the third most common chronic brain disorder. Modafinil is an awakening agent approved for narcolepsy. In addition to its clinical uses some reports revealed that modafinil was associated with some alterations in seizure threshold. The purpose of this study was to clarify the effect of acute administration of modafinil in clonic seizure threshold (CST) induced by pentylenetetrazole in mice and the involvement of glutamate, nitric oxide, gamma amino butyric acid (GABA), and serotonin systems in this feature. Modafinil at 80 and 150 mg/kg showed anti- and pro-convulsant effects respectively and expressed maximum anti- and pro-convulsant activities at 30 min after injection. Both modulatory effects were blunted by pretreatment of l-NAME [nonspecific nitric oxide synthase (NOS) inhibitor; 10 mg/kg, i.p.], 7-nitroindazole (a neuronal NOS inhibitor; 40 mg/kg, i.p.), and aminoguanidine (an inducible NOS inhibitor; 50 mg/kg, i.p.). Injection of the NOS precursor l-arginine (60 mg/kg, i.p.) before modafinil did not change the anti-convulsant effect, while thoroughly reversed the pro-convulsant one. Our experiments displayed that administration of diazepam (a GABA_A receptor agonist; 0.02 mg/kg, i.p.) and MK-801 (a NMDA receptor antagonist; 0.05 mg/kg, i.p.) before different doses of modafinil significantly increased CST. Finally, pretreatment of citalopram (a selective serotonin reuptake inhibitor; 0.1 mg/kg, i.p.) did not modify the convulsant activities of modafinil. Therefore, nitric oxide system may mediate anti-convulsant activity, while glutamate, nitric oxide, and GABA pathways may involve in pro-convulsant property. Serotonin receptors have no role on convulsant effects of modafinil.     

The prevalence of factor V Leiden,prothrombin G20210A and methylenetetrahydrofolate reductase polymorphism C677T among G6PD deficient individuals from Western Iran

It has been suggested that the allele frequency of thrombophilic mutations is affected by glucose-6-phosphate dehydrogenase (G6PD) deficiency. The prevalence of thrombophilic mutations were studied in sixty G6PD deficient individuals including 57 males and three females with the mean age of 15 ± 3.08 and 110 age and sex matched healthy individuals consisted of 95 males and 15 females with the mean age of 16.19 ± 2.17 from the Kermanshah Province of Iran. Using a combination of PCR-RFLP technique, single strand conformation polymorphism (SSCP) analysis and DNA sequencing polymorphic G6PD mutations were identified. The factor V Leiden, prothrombin G20210A and methylenetetrahydrofolate reductase (MTHFR) C677T were detected by PCR-RFLP method using MnlI, HindIII and HinfI restriction enzymes, respectively. Three mutations, G6PD Mediterranean, G6PD Chatham and G6PD Cosenza were identified in 60 G6PD deficient individuals with highest prevalence of G6PD Mediterranean (91.6%). In G6PD deficient individuals the prevalence of factor V Leiden tended to be higher (5%) compared to healthy individuals (2.7%). The prevalence of prothrombin G20210A mutation in G6PD deficient individuals was 1.7%. However, in normal subjects the prevalence of this mutation was 2.7%. The frequency of T allele in G6PD deficient individuals were insignificantly higher (29.16%) than those in healthy individuals (26.8%). Our finding indicates that the prevalence of factor V Leiden, prothrombin G20210A and MTHFR C677T in G6PD deficient individuals is not statistically different compared to normal subjects and G6PD deficiency is not associated with these thrombophilic mutations in Western Iran.     

Lamprey <Emphasis Type="Italic">snail</Emphasis> highlights conserved and novel patterning roles in vertebrate embryos

snail genes mark presumptive mesoderm across bilaterian animals. In gnathostome vertebrates, snail genes are a multimember family that are also markers of premigratory neural crest (pnc) and some postmigratory neural crest derivatives in the pharyngeal arches. Previous studies of nonvertebrate chordates indicate that they have single snail genes that retain ancestral functions in mesoderm development and perhaps in specification of a pnc-like cell population. Lampreys are the most basal extant vertebrates, with well-defined developmental morphology. Here, we identify a single snail gene from the lamprey Petromyzon marinus that is the phylogenetic outgroup of all gnathostome snail genes. This single lamprey snail gene retains ancestral snail patterning domains present in nonvertebrate chordates. Lamprey snail is also expressed in tissues that are broadly equivalent to the combined sites of expression of all three gnathostome snail paralogy groups, excepting in embryonic tissues that are unique to gnathostomes. Importantly, while snail does not appear to demarcate an early neural crest population in lampreys as it does in gnathostomes, it may be involved in later neural crest development. Together, our results indicate that significant cis-regulatory innovation occurred in a single snail gene before the vertebrate radiation, and significant subfunctionalization occurred after snail gene duplications in the gnathostome lineages.     

Analysis of beta-hemolysis in human blood agars by Streptococcus pyogenes

The aim of the study was to assess the reliability of human blood agar media (HuBA) in identifying Streptococcus pyogenes by hemolysis analysis. We analyze several factors that might affect the accuracy of HuBA media for microbial analysis, including incubation time, blood group, Rh factor and presence of antistreptolysin-o.     

FGF-2, IL-1beta and TGF-beta regulate fibroblast expression of S100A8

Growth factors, including fibroblast growth factor-2 (FGF-2) and transforming growth factor-beta (TGF-beta) regulate fibroblast function, differentiation and proliferation. S100A8 and S100A9 are members of the S100 family of Ca2+-binding proteins and are now accepted as markers of inflammation. They are expressed by keratinocytes and inflammatory cells in human/murine wounds and by appropriately activated macrophages, endothelial cells, epithelial cells and keratinocytes in vitro. In this study, regulation and expression of S100A8 and S100A9 were examined in fibroblasts. Endotoxin (LPS), interferon gamma (IFNgamma), tumour-necrosis factor (TNF) and TGF-beta did not induce the S100A8 gene in murine fibroblasts whereas FGF-2 induced mRNA maximally after 12 h. The FGF-2 response was strongly enhanced and prolonged by heparin. Interleukin-1beta (IL-1beta) alone, or in synergy with FGF-2/heparin strongly induced the gene in 3T3 fibroblasts. S100A9 mRNA was not induced under any condition. Induction of S100A8 in the absence of S100A9 was confirmed in primary fibroblasts. S100A8 mRNA induction by FGF-2 and IL-1beta was partially dependent on the mitogen-activated-protein-kinase pathway and dependent on new protein synthesis. FGF-2-responsive elements were distinct from the IL-1beta-responsive elements in the S100A8 gene promoter. FGF-2-/heparin-induced, but not IL-1beta-induced responses were significantly suppressed by TGF-beta, possibly mediated by decreased mRNA stability. S100A8 in activated fibroblasts was mainly intracytoplasmic. Rat dermal wounds contained numerous S100A8-positive fibroblast-like cells 2 and 4 days post injury; numbers declined by 7 days. Up-regulation of S100A8 by FGF-2/IL-1beta, down-regulation by TGF-beta, and its time-dependent expression in wound fibroblasts suggest a role in fibroblast differentiation at sites of inflammation and repair.     

Nuclear Localization of the Mitochondrial Factor HIGD1A during Metabolic Stress

Cellular stress responses are frequently governed by the subcellular localization of critical effector proteins. Apoptosis-inducing Factor (AIF) or Glyceraldehyde 3-Phosphate Dehydrogenase (GAPDH), for example, can translocate from mitochondria to the nucleus, where they modulate apoptotic death pathways. Hypoxia-inducible gene domain 1A (HIGD1A) is a mitochondrial protein regulated by Hypoxia-inducible Factor-1α (HIF1α). Here we show that while HIGD1A resides in mitochondria during physiological hypoxia, severe metabolic stress, such as glucose starvation coupled with hypoxia, in addition to DNA damage induced by etoposide, triggers its nuclear accumulation. We show that nuclear localization of HIGD1A overlaps with that of AIF, and is dependent on the presence of BAX and BAK. Furthermore, we show that AIF and HIGD1A physically interact. Additionally, we demonstrate that nuclear HIGD1A is a potential marker of metabolic stress in vivo, frequently observed in diverse pathological states such as myocardial infarction, hypoxic-ischemic encephalopathy (HIE), and different types of cancer. In summary, we demonstrate a novel nuclear localization of HIGD1A that is commonly observed in human disease processes in vivo.