HOTAIR but not ANRIL long non‐coding RNA contributes to the pathogenesis of multiple sclerosis

Studies have revealed that dysregulation in gene expression is one of the main aspects of multiple sclerosis (MS) pathogenesis. Although the molecular pathways underlying the immunomodulatory role of vitamin D (VD) in MS is not completely elucidated, VD has more recently become a topic of interest in immune regulation and is widely administered to patients with MS as an immunomodulatory supplement. Long non‐coding RNAs (lncRNAs) are known to play important roles in regulation of gene expression via different mechanisms. Given that VD‐related genes are regulated by epigenetic mechanisms, here we aimed to evaluate the role of VD in combination with HOTAIR and ANRIL lncRNAs using in vivo, in vitro and in silico experiments in MS pathogenesis. Our data revealed that HOTAIR but not ANRIL lncRNA is probably involved in the pathogenesis of MS and experimental autoimmune encephalomyelitis through an unclear mechanism and it seems that by affecting the expression, inflammation and VD can influence HOTAIR‐related mechanisms, which require further study.     

PKC,ERK/p38 MAP kinases and NF‐κB targeted signalling play a role in the expression and release of IL‐1β and CXCL8 in Porphyromonas gingivalis‐infected THP1 cells

Porphyromonas gingivalis is a keystone pathogen in periodontitis and is gaining importance in cardiovascular pathogenesis. Protease‐activated receptors (PARs), toll‐like receptors (TLRs) and nucleotide‐binding oligomerization domain (NOD) on monocytes recognize the structural components on P. gingivalis, inducing inflammatory intermediates. Here, we elucidate the modulation of PARs, TLRs, NODs, and the role of MAPK and NF‐κB in IL‐1β and CXCL8 release. THP1 cells were stimulated with P. gingivalis wild‐type W50 and its isogenic gingipain mutants: Rgp mutant E8 and Kgp mutant K1A. We observed modulation of PARs, TLRs, NOD, IL‐1β and CXCL8 expression by P. gingivalis. Gingipains hydrolyse IL‐1β and CXCL8, which is more evident for IL‐1β accumulation at 24 h. Inhibition of PKC (protein kinase C), p38 and ERK (extracellular signal‐regulated kinases) partially reduced P. gingivalis‐induced IL‐1β at 6 h, whereas PKC and ERK reduced CXCL8 at both 6 and 24 h. Following NF‐κB inhibition, P. gingivalis‐induced IL‐1β and CXCL8 were completely suppressed to basal levels. Overall, TLRs, PARs and NOD possibly act in synergy with PKC, MAPK ERK/p38 and NF‐κB in P. gingivalis‐induced IL‐1β and CXCL8 release from THP1 cells. These pro‐inflammatory cytokines could affect leucocytes in circulation and exacerbate other vascular inflammatory conditions such as atherosclerosis.     

Association of the HLA‐B27 antigen and the CTLA4 gene CT60/rs3087243 polymorphism with ankylosing spondylitis in Algerian population: A case–control study

Ankylosing spondylitis (AS) is a complex inflammatory disease that represents a major health problem both in Algeria and worldwide. Several lines of evidence support that genetic risk factors play a role in AS etiology and the CTLA4 gene has attracted a considerable attention. In this study, we were interested in evaluating the HLA‐B27 frequency and in exploring the CTLA4 gene in a sample of the North African population. The dataset of the current study is composed of 81 patients with AS and 123 healthy controls. All samples were genotyped by TaqMan^®allelic discrimination assay. The genetic risk of the HLA‐B27 specificity and the CTLA4/CT60 polymorphism were assessed by odds ratios (OR) with 95% confidence intervals (CI). High spondylitis risk was detected for HLA‐B27 allele (OR= 14.62, p = 10^?6) in addition to a significant association of the CT60*G allele (OR= 1.89, p = .002). After gender and age stratifications, the association of the CT60*G allele was still significant in females sample (OR= 2.10, p = .001) and when age up to 30 years (OR = 2.21, p = .008). Interestingly, the CT60*G allele revealed an increased spondylitis risk in the B27 negative group (OR= 2.81, p = .006). The present work showed in West Algerian population that the HLA‐B27 antigen and the variation in the CTLA4 3′UTR region played an important role in the ankylosing spondylitis susceptibility. The heterogeneity of this disease is deduced by genetic difference found between B27+ and B27? groups.     

A high‐throughput assay for the measurement of uropathogenic Escherichia coli attachment to urinary bladder cells

Strains of uropathogenic Escherichia coli (UPEC) are the major causative agent of urinary tract infections (UTI), the most common infectious diseases in the world. Their ability to attach and enter into cells in the urinary tract is a limiting step for their pathogenicity. Many studies are thus focussing on these key mechanisms to propose new therapeutic strategies. To facilitate such studies, we developed a fast and high‐throughput assay which makes it possible to monitor the interaction of UPEC with cultured human uroepithelial cells. This assay allows measurement of the in vitro association of fluorescently labelled clinical isolates with bladder epithelial cells using flow cytometry in a microplate format. The assay was sensitive enough to detect variations between isolates expressing different adhesins and virulence factors and the inhibitory effect of proanthocyanidins. Thus we have developed a fast and robust assay which allows us to measure variations in the adhesion properties of UPEC to human bladder cells. This novel assay will be valuable for the study of initial steps of pathogenesis in UTI and for the screening or validation of inhibitory molecules.     

Inhibitory effect of chromogenic culture media on the growth of Rhodotorula: relevance to the diagnosis of Rhodotorula spp. infections

With the increasing incidence and diverse etiologies of fungal infections, chromogenic yeast culture media are increasingly used for routine diagnosis. Rhodotorula species, which are characterized by the production of carotenoid pigments, are considered as emerging opportunistic pathogens. We recently diagnosed two fungemia due to Rhodotorula spp. and noticed that in both cases, the yeast failed to grow in subculture on the chromogenic yeast culture medium. This study was thus undertaken to investigate more thoroughly the ability (or inability) of Rhodotorula species to grow on different commercially available chromogenic media for yeast. Eighteen Rhodotorula spp. were checked for their ability to grow on four chromogenic yeast culture media: CHROMagar Candida (BD), Candi 4 Select (Biorad), Brilliance Candida (Oxoid), and Candida ID 2 (BioMerieux). All the Rhodotorula spp. strains grew on Brilliance and Candida ID 2, while only six isolates grew on Candi 4, and seven on CHROMagar. Two chromogenic yeast culture media showed a significant inhibitory effect on the growth of Rhodotorula species. As all Rhodotorula species are resistant to echinocandins and fluconazole, it is essential to isolate and identify these yeast quickly to initiate appropriate amphotericin B antifungal treatment as early as possible. The choice of media for routine use should take into account the ability of different media to allow all emerging fungal pathogens to grow.     

cAMP‐induced activation of protein kinase A and p190B RhoGAP mediates down‐regulation of TC10 activity at the plasma membrane and neurite outgrowth

Cyclic AMP plays a pivotal role in neurite growth. During outgrowth, a trafficking system supplies membrane at growth cones. However, the cAMP‐induced signaling leading to the regulation of membrane trafficking remains unknown. TC10 is a Rho family GTPase that is essential for specific types of vesicular trafficking. Recent studies have shown a role of TC10 in neurite growth in NGF‐treated PC12 cells. Here, we investigated a mechanical linkage between cAMP and TC10 in neuritogenesis. Plasmalemmal TC10 activity decreased abruptly after cAMP addition in neuronal cells. TC10 was locally inactivated at extending neurite tips in cAMP‐treated PC12 cells. TC10 depletion led to a decrease in cAMP‐induced neurite outgrowth. Constitutively active TC10 could not rescue this growth reduction, supporting our model for a role of GTP hydrolysis of TC10 in neuritogenesis by accelerating vesicle fusion. The cAMP‐induced TC10 inactivation was mediated by PKA. Considering cAMP‐induced RhoA inactivation, we found that p190B, but not p190A, mediated inactivation of TC10 and RhoA. Upon cAMP treatment, p190B was recruited to the plasma membrane. STEF depletion and Rac1‐N17 expression reduced cAMP‐induced TC10 inactivation. Together, the PKA‐STEF‐Rac1‐p190B pathway leading to inactivation of TC10 and RhoA at the plasma membrane plays an important role in cAMP‐induced neurite outgrowth.     

Airborne olive pollen counts are not representative of exposure to the major olive allergen Ole e 1

Pollen is routinely monitored, but it is unknown whether pollen counts represent allergen exposure. We therefore simultaneously determined olive pollen and Ole e 1 in ambient air in Córdoba, Spain, and Évora, Portugal, using Hirst‐type traps for pollen and high‐volume cascade impactors for allergen. Pollen from different days released 12‐fold different amounts of Ole e 1 per pollen (both locations P < 0.001). Average allergen release from pollen (pollen potency) was much higher in Córdoba (3.9 pg Ole e 1/pollen) than in Évora (0.8 pg Ole e 1/pollen, P = 0.004). Indeed, yearly olive pollen counts in Córdoba were 2.4 times higher than in Évora, but Ole e 1 concentrations were 7.6 times higher. When modeling the origin of the pollen, >40% of Ole e 1 exposure in Évora was explained by high‐potency pollen originating from the south of Spain. Thus, olive pollen can vary substantially in allergen release, even though they are morphologically identical.     

Confirming the recessive inheritance of SCN1B mutations in developmental epileptic encephalopathy

Dominant SCN1B mutations are known to cause several epilepsy syndromes in humans. Only 2 epilepsy patients to date have been reported to have recessive mutations in SCN1B as the likely cause of their phenotype. Here, we confirm the recessive inheritance of 2 novel SCN1B mutations in 5 children from 3 families with developmental epileptic encephalopathy. The recessive inheritance and early death in these patients is consistent with the Dravet‐like phenotype observed in Scn1b^?/? mice. The ‘negative’ clinical exome in one of these families highlights the need to consider recessive mutations in the interpretation of variants in typically dominant genes.     

Proteinase K is an activator for the male‐dependent spermiogenesis pathway in Caenorhabditis elegans: Its application to pharmacological dissection of spermiogenesis

Caenorhabditis elegans spermiogenesis involves spermatid activation into spermatozoa. Activation occurs through either SPE‐8 class‐dependent or class‐independent pathways. Pronase (Pron) activates the SPE‐8 class‐dependent pathway, whereas no in vitro tools are available to stimulate the SPE‐8 class‐independent pathway. Thus, whether there is a functional relationship between these two pathways is currently unclear. In this study, we found that proteinase K (ProK) can activate the SPE‐8 class‐independent pathway. In vitro spermiogenesis assays using Pron and ProK suggested that SPE‐8 class proteins act in the hermaphrodite‐ and male‐dependent spermiogenesis pathways and that some spermatid proteins presumably working downstream of spermiogenesis pathways, including MAP kinases, are preferentially involved in the SPE‐8 class‐dependent pathway. We screened a library of chemicals, and a compound that we named DDI‐1 inhibited both Pron‐ and ProK‐induced spermiogenesis. To our surprise, several DDI‐1 analogues that are structurally similar to DDI‐1 blocked Pron, but not ProK, induced spermiogenesis. Although the mechanism by which DDI‐1 blocks spermiogenesis is yet unknown, we have begun to address this issue by selecting two DDI‐1‐resistant mutants. Collectively, our data support a model in which C. elegans male and hermaphrodite spermiogenesis each has its own distinct, parallel pathway.     

Evaluation of a PCR method to determine the clinical significance of blood cultures with Staphylococcus epidermidis in patients with hematological malignancies

The aim was to investigate whether the detection and quantification of Staphylococcus epidermidis DNA in blood could distinguish S. epidermidis blood stream infections (BSIs) from blood culture contaminations in patients with hematological malignancies. The hld gene was chosen to identify S. epidermidis DNA and DNA in blood samples was detected by real‐time PCR. Blood samples were obtained simultaneously with blood cultures positive for S. epidermidis (n = 30), during blood culture‐negative episodes (n = 10) and episodes of bacteremia with other bacteria than S. epidermidis (n = 4) and from healthy blood donors (n = 10). In addition, DNA from S. epidermidis and a selection of other bacterial species were analyzed. Three different sets of criteria were used to classify episodes with positive blood cultures with S. epidermidis as BSIs or contaminations. All DNA preparations from S. epidermidis (n = 48) were hld‐positive, but other bacterial species (n = 13) were negative. Sixteen (53%) of 30 blood samples from patients with blood cultures positive for S. epidermidis were hld‐positive, but none of the controls. There was no clear association between a positive hld PCR and episodes interpreted as BSIs. In conclusion, hld PCR failed to distinguish S. epidermidis BSIs from blood culture contaminations in patients with hematological malignancies.     

Ambroxol inhibits mucoid conversion of Pseudomonas aeruginosa and contributes to the bactericidal activity of ciprofloxacin against mucoid P. aeruginosa biofilms

Pseudomonas aeruginosa is an opportunistic human pathogen that can cause severe infections in immunocompromised individuals. Because it forms biofilms, which protect against host immune attack and increase resistance to conventional antibiotics, mucoid P. aeruginosa is nearly impossible to eradicate. Moreover, mucoid conversion of P. aeruginosa in cystic fibrosis (CF) patients leads to poor outcomes. This conversion is mainly due to mucA gene mutation, which is thought to be induced by polymorphonuclear leukocytes (PMNs) and the reactive oxygen species they release. Ambroxol, a mucolytic agent with antioxidant characteristics, is used clinically, and this compound has recently been demonstrated to possess anti‐biofilm properties. In this study, we found that ambroxol inhibits the H₂O₂‐mediated conversion of P. aeruginosa from a non‐mucoid to a mucoid phenotype, an effect that is due to its antioxidant property against H₂O₂. Furthermore, the bactericidal activity of ciprofloxacin against mucoid P. aeruginosa biofilms was increased in vitro when used in combination with ambroxol.