Characterization of water and wildlife strains as a subgroup of Campylobacter jejuni using DNA microarrays

Campylobacter jejuni is the leading cause of human bacterial gastroenteritis worldwide, but source attribution of the organism is difficult. Previously, DNA microarrays were used to investigate isolate source, which suggested a non‐livestock source of infection. In this study we analysed the genome content of 162 clinical, livestock and water and wildlife (WW) associated isolates combined with the previous study. Isolates were grouped by genotypes into nine clusters (C1 to C9). Multilocus sequence typing (MLST) data demonstrated that livestock associated clonal complexes dominated clusters C1–C6. The majority of WW isolates were present in the C9 cluster. Analysis of previously reported genomic variable regions demonstrated that these regions were linked to specific clusters. Two novel variable regions were identified. A six gene multiplex PCR (mPCR) assay, designed to effectively differentiated strains into clusters, was validated with 30 isolates. A further five WW isolates were tested by mPCR and were assigned to the C7‐C9 group of clusters. The predictive mPCR test could be used to indicate if a clinical case has come from domesticated or WW sources. Our findings provide further evidence that WW C. jejuni subtypes show niche adaptation and may be important in causing human infection.     

Role of thrombin in the pathogenesis of atherosclerosis

Atherosclerosis is an arterial disease associated with inflammation. Thrombin is a procoagulant and proinflammatory serine protease that contributes to the pathology of atherosclerosis by enhancing the expression of cell adhesion molecules, inducing the secretion of proinflammatory cytokines, activating inflammatory responses in atherosclerotic plaques, stimulating proliferation of aortic smooth muscle cells, and exacerbating vascular lesions at sites of injury. Hence, thrombin appears to be an important target for treatment of atherosclerosis and thrombin pharmacological inhibitors have significant therapeutic potency for suppressing inflammatory responses in cardiovascular diseases. This review summarizes the proinflammatory signaling functions of thrombin as well as the therapeutic potency of thrombin inhibitors in the pathogenesis of atherosclerosis and hence their potential therapeutic value in this condition.     

Regulation of the Ste20-like kinase, SLK: involvement of activation segment phosphorylation

Expression and activation of the Ste20-like kinase, SLK, is increased during kidney development and recovery from ischemic acute kidney injury. SLK promotes apoptosis, and it may regulate cell survival during injury or repair. This study addresses the role of phosphorylation in the regulation of kinase activity. We mutated serine and threonine residues in the putative activation segment of the SLK catalytic domain and expressed wild type (WT) and mutant proteins in COS-1 or glomerular epithelial cells. Compared with SLK WT, the T183A, S189A, and T183A/S189A mutants showed reduced in vitro kinase activity. SLK WT, but not mutants, increased activation-specific phosphorylation of c-Jun N-terminal kinase (JNK) and p38 kinase. Similarly, SLK WT stimulated activator protein-1 reporter activity, but activation of activator protein-1 by the three SLK mutants was ineffective. To test if homodimerization of SLK affects phosphorylation, the cDNA encoding SLK amino acids 1-373 (which include the catalytic domain) was fused with a cDNA for a modified FK506-binding protein, Fv (Fv-SLK 1-373). After transfection, the addition of AP20187 (an FK506 analog) induced regulated dimerization of Fv-SLK 1-373. AP20187-stimulated dimerization enhanced the kinase activity of Fv-SLK 1-373 WT. In contrast, kinase activity of Fv-SLK 1-373 T183A/S189A was weak and was not enhanced after dimerization. Finally, apoptosis was increased after expression of Fv-SLK 1-373 WT but not T183A/S189A. Thus, phosphorylation of Thr-183 and Ser-189 plays a key role in the activation and signaling of SLK and could represent a target for novel therapeutic approaches to renal injury.     

Combinational therapy of lithium and human neural stem cells in rat spinal cord contusion model

A large number of treatment approaches have been used for spinal cord injury improvement, a medically incurable disorder, and subsequently stem cell transplantation appears to be a promising strategy. The main objective of this study is to ascertain whether combinational therapy of human neural stem cells (hNSCs) together with lithium chloride improves cell survival, proliferation, and differentiation in a rat spinal contusion model, or not. Contusive spinal cord injury was implemented on Wistar male rats. Experimental groups comprised of: control, hNSCs transplanted, lithium chloride (Li), and hNSCs and lithium chloride (hNSCs + Li). In every experimental group, locomotor activity score and motor evoked potential (MEP) were performed to evaluate motor recovery as well as histological assessments to determine mechanisms of improvement. In accordance with our results, the hNSCs + Li and the Li groups showed significant improvement in locomotor scores and MEP. Also, Histological assessments revealed that transplanted hNSCs are capable of differentiation and migration along the spinal cord. Although NESTIN-positive cells were proliferated significantly in the Lithium group in comparison with control and the hNSCs + Li groups, the quantity of ED1 cells in the hNSCs + Li was significantly larger than the other two groups. Our results demonstrate that combinational therapy of hNSCs with lithium chloride and lithium chloride individually are adequate for ameliorating more than partial functional recovery and endogenous repair in spinal cord-injured rats.     

In vitro characterization of subventricular zone isolated neural stem cells,from adult monkey and rat brain

Neural stem cells (NSCs) are multipotent, self-renewable cells who are capable of differentiating into neurons, astrocytes, and oligodendrocytes. NSCs reside at the subventricular zone (SVZ) of the adult brain permanently to guarantee a lifelong neurogenesis during neural network plasticity or undesirable injuries. Although the specious inaccessibility of adult NSCs niche hampers their in vivo identification, researchers have been seeking ways to optimize adult NSCs isolation, expansion, and differentiation, in vitro. NSCs were isolated from rhesus monkey SVZ, expanded in vitro and then characterized for NSCs-specific markers expression by immunostaining, real-time PCR, flow cytometry, and cell differentiation assessments. Moreover, cell survival as well as self-renewal capacity were evaluated by TUNEL, Live/Dead and colony assays, respectively. In the next step, to validate SVZ-NSCs identity in other species, a similar protocol was applied to isolate NSCs from adult rat’s SVZ as well. Our findings revealed that isolated SVZ-NSCs from both monkey and rat preserve proliferation capacity in at least nine passages as confirmed by Ki67 expression. Additionally, both SVZ-NSCs sources are capable of self-renewal in addition to NESTIN, SOX2, and GFAP expression. The mortality was measured meager with over 95% viability according to TUNEL and Live/Dead assay results. Eventually, the multipotency of SVZ-NSCs appraised authentic after their differentiation into neurons, astrocytes, and oligodendrocytes. In this study, we proposed a reliable method for SVZ-NSCs in vitro maintenance and identification, which, we believe is a promising cell source for therapeutic approach to recover neurological disorders and injuries condition.

     

Optimization of date syrup as a novel medium for lovastatin production by <Emphasis Type="Italic">Aspergillus terreus</Emphasis> ATCC 20542 and analyzing assimilation kinetic of carbohydrates

Lovastatin is a statin drug, which lowers cholesterol level in blood due to inhibition of (S)-3-hydroxy-3-methylglutaryl-CoA reductase. Date syrup is a rich medium for microbial growth and metabolite production. The main carbohydrates present in the date syrup are glucose and fructose. In this study, date syrup was used as a complex and bioresource medium for lovastatin production by Aspergillus terreus in the submerged cultivation. Optimization of the date syrup medium in order to achieve the highest titers of lovastatin and biomass was carried out. Four factors were studied by response surface methodology including concentration of date syrup carbohydrates, yeast extract concentration, pH, and rotation speed of the shaker. Optimal conditions for these factors found were as follows: concentration of date syrup carbohydrates, 64 g/l; yeast extract concentration, 15 g/l; pH, 6.5; and agitation speed, 150 rpm. It gave lovastatin concentration of 105.6 mg/l. Next, batch cultures in the optimal conditions were performed in a 2.5-l working volume bioreactor and led to the lovastatin titer of 241.1 mg/l during 12 days. Aspergillus terreus showed diauxic growth in the optimized medium with a shift from glucose to fructose assimilation during the run. Glucose and fructose assimilation kinetic parameters revealed that more lovastatin is produced during glucose assimilation, while more biomass was formed during fructose assimilation.     

IFN‐β rescues neurodegeneration by regulating mitochondrial fission via STAT5, PGAM5, and Drp1

Mitochondrial homeostasis is essential for providing cellular energy, particularly in resource‐demanding neurons, defects in which cause neurodegeneration, but the function of interferons (IFNs) in regulating neuronal mitochondrial homeostasis is unknown. We found that neuronal IFN‐β is indispensable for mitochondrial homeostasis and metabolism, sustaining ATP levels and preventing excessive ROS by controlling mitochondrial fission. IFN‐β induces events that are required for mitochondrial fission, phosphorylating STAT5 and upregulating PGAM5, which phosphorylates serine 622 of Drp1. IFN‐β signaling then recruits Drp1 to mitochondria, oligomerizes it, and engages INF2 to stabilize mitochondria–endoplasmic reticulum (ER) platforms. This process tethers damaged mitochondria to the ER to separate them via fission. Lack of neuronal IFN‐β in the Ifnb ^–/– model of Parkinson disease (PD) disrupts STAT5‐PGAM5‐Drp1 signaling, impairing fission and causing large multibranched, damaged mitochondria with insufficient ATP production and excessive oxidative stress to accumulate. In other PD models, IFN‐β rescues dopaminergic neuronal cell death and pathology, associated with preserved mitochondrial homeostasis. Thus, IFN‐β activates mitochondrial fission in neurons through the pSTAT5/PGAM5/^S622Drp1 pathway to stabilize mitochondria/ER platforms, constituting an essential neuroprotective mechanism.