MiR-137: an important player in neural development and neoplastic transformation.

MicroRNAs (miRNAs) represent an important class of small regulatory RNAs that control gene expression posttranscriptionally by targeting mRNAs for degradation or translation inhibition. Early studies have revealed a complex role for miRNAs in major biological processes such as development, differentiation, growth and metabolism. MiR-137 in particular, has been of great interest due to its critical role in brain function and putative involvement in the etiology of both neuropsychiatric disorders and cancer. Several lines of evidence suggest that development, differentiation and maturation of the nervous system is strongly linked to the expression of miR-137 and its regulation of a large number of downstream target genes in various pathways. Dysregulation of this molecule has also been implicated in major mental illnesses through its position in a variant allele highly associated with schizophrenia in the largest mega genome-wide association studies. Interestingly, miR-137 has also been shown to act as a tumor suppressor, with numerous studies finding reduced expression in neoplasia including brain tumor. Restoration of miR-137 expression has also been shown to inhibit cell proliferation, migration and metastasis, and induce cell cycle arrest, differentiation and apoptosis. These properties of miR-137 propose its potential for prognosis, diagnosis and as a therapeutic target for treatment of several human neurological and neoplastic disorders. In this review, we provide details on the discovery, targets, function, regulation and disease involvement of miR-137 with a broad look at recent discovery in this area.

Effects of permethrin on biomarkers in Mediterranean clams (Ruditapes decussatus).

The present study was focused on the assessment of Catalase (CAT) and Acetylcholinesterase (AChE) activities in Mediterranean clams (Ruditapes decussatus) exposed to 50, 100 and 150 µg/L of Permethrin for 5, 10, 15, 20 and 25 days. In water, the measured concentrations of Permethrin in the treated aquariums were respectively 16.66, 38.24 and 55.61 µg/L. Results showed that CAT activity was increased after 5 days of exposure to high concentration reaching maximum value of 10.14 µmol/min/mg proteins after 25 days. However, no significant changes in AChE activity after 5 days of exposure were detected in all treated groups. AChE activity was significantly inhibited after 10 days with 100 and 150 µg/L and still depending on concentration and time. Maximum inhibition of AChE activity was reached after 25 days with the highest concentration of Permethrin. Our data indicated that exposure to Permethrin modifies biomarker profiles inducing oxidative stress and reducing AChE activity in Mediterranean clams.

Responses of a free-living marine nematode community to mercury contamination: results from microcosm experiments.

A microcosm experiment was used to examine the effects of mercury contamination on a free-living nematode community in a Tunisian lagoon. Sediments were contaminated with three mercury concentrations (low, 0.084 ppm; medium, 0.167 ppm; and high, 0.334 ppm), and effects were examined after 60 days. Results from multiple-comparison tests showed significant differences between nematode assemblages from undisturbed control and those from mercury treatments. Most univariate measures decreased significantly with increasing level of Hg contamination. Results from multivariate analyses of the species abundance data demonstrated that responses of nematode species to mercury contamination were varied: Araeolaimus bioculatus was eliminated at all the mercury doses tested and seemed to be an intolerant species to mercury contamination; Marylynnia stekhoveni increased at low and medium concentrations and appeared to be an "opportunistic" species at these doses, whereas Prochromadorella neapolitana, which increased at all doses tested (0.084, 0.167, and 0.334 ppm), seemed to be a "mercury-resistant" species.

Circular RNAs are temporospatially regulated throughout development and ageing in the rat.

Circular RNAs (circRNAs) are covalently closed structural isoforms of linear mRNA which have been observed across a broad range of species and tissues. Here, we provide a comprehensive circRNAs expression catalogue for the rat including 8 organs of both sexes during 4 developmental stages using a public RNAseq dataset. These analyses revealed thousands of circular RNA species, many expressed in an organ-specific manner along with their host genes which were enriched with tissue-specific biological functions. A large number of circRNAs also displayed a developmental-dependent expression pattern and are accumulated during ageing. CircRNAs also displayed some sexually dimorphic expression, with gender associated differences observed in various tissues and developmental stages. These observations suggest that circRNAs are dynamically expressed in a spatial-, temporal- and gender-specific manner in mammals, and may have important biological function in differentiation, development and aging.

In vitro activity of kombucha tea ethyl acetate fraction against Malassezia species isolated from seborrhoeic dermatitis.

BACKGROUND AND PURPOSE: Seborrheic dermatitis is a chronic and recurrent superficial dermatitis in which Malassezia species play an important role. There are different Malassezia species, which have been recently reported to be resistant to common antifungals. Natural sources can be useful alternatives to reduce the emergence of this resistance. Kombucha tea is believed to have potential antimicrobial properties. Regarding this, the present study aimed to investigate the antifungal activity of Kombucha tea ethyl acetate fraction (KEAF) against Malassezia species obtained from the patients with seborrheic dermatitis. MATERIALS AND METHODS: A total of 23 clinical isolates were identified by direct microscopic examination and Tween assimilation, and then confirmed by DNA sequencing of ITS regions for Malassezia species. Kombucha tea was fractionated using ethyl acetate (1:2 v/v). The minimum inhibitory concentration (MIC) microdilution assay was used to evaluate the anti-Malssezia activity of KEAF at three concentrations of 10, 40, and 80 mg/mL. RESULTS: The results of the DNA sequence analysis indicated that M. furfur (39.13%) was the predominant species, followed by M. globosa (30.43%), M. sloofie (13.04%), M. sympodialis (13.04%), and M. restricta (4.34%), respectively. Furthermore, KEAF showed inhibitory activity against Malassezia species. Accordingly, KEAF had the lowest and highest MIC value against M. sloofie and M. restricta, respectively. Moreover, the inhibitory effect of the extract was equivalent to that of ketoconazole at 4.8 µg/mL. CONCLUSION: The findings of the current study highlighted the antifungal properties of KEAF. Therefore, this extract can be promoted as complementary medicine for the treatment of the infections caused by Malassezia.

Effects of two lubricant oils on marine nematode assemblages in a laboratory microcosm experiment.

The effects of two lubricating oils on nematode assemblages of a Tunisian lagoon were investigated in a microcosm experiment. Sediment from a pristine site in Ghar El Melh lagoon (Western Mediterranean) was treated with either mineral oil (Mobil 20 W-50), a synthetic lubricant (Mobil 0 W-40), the same two lubricants after use in a vehicle, and effects were examined after 5 weeks. Univariate analysis showed significant differences between most univariate indices of the nematode assemblages in all the lubricant treatments as compared to the control. Total nematode abundance (I), species richness (d) and number of species (S) decreased significantly in all lubricant contaminated microcosms. However, evenness was not affected in all treated replicates except in used mineral lubricant treatment where it was significantly higher than in the control. Diversity (H') was only altered in synthetic lubricant treatments. Results from multivariate analyses of the species abundance data demonstrated that responses of nematode species to the two lubricants treatments were varied: Daptonema trabeculosum was eliminated in all lubricant treatments and seemed to be an intolerant species to oil contamination. Spirinia gerlachi increased in mineral lubricant treatments ("clean" and used) but was eliminated in all synthetic lubricant treatments. This species could be categorized as "resistant" to mineral oil contamination and intolerant to synthetic lubricant contamination. Terschellingia longicaudata increased only in synthetic lubricant treatments ("clean" and used) and appeared to be a "synthetic oil-resistant" species.

Effects of increasing levels of nickel contamination on structure of offshore nematode communities in experimental microcosms.

A microcosm experiment was used to examine the effects of nickel on offshore nematode communities of a Tunisian coastal zone (Southwestern Mediterranean Sea). Sediments were contaminated with three nickel concentrations [low (250 ppm), medium (550 ppm) and high (900 ppm)], and effects were examined after 30 days. Results showed significant differences between nematode assemblages from undisturbed controls and those from nickel treatments. Most univariates measures, including diversity and species richness, decreased significantly with increasing level of Ni contamination. Results from multivariate analyses of the species abundance data demonstrated that responses of nematode species to the nickel treatments were varied: Leptonemella aphanothecae was eliminated at all the nickel doses tested and seemed to be intolerant species to nickel contamination; Daptonema normandicum, Neochromadora trichophora and Odontophora armata which significantly increased at 550 ppm nickel concentration appeared to be "opportunistic" species at this dose whereas Oncholaimus campylocercoides and Bathylaimus capacosus which increased at all doses tested (250, 550 and 900 ppm) seemed to be "nickel-resistant" species.

Individual and combined effects of cadmium and diesel on a nematode community in a laboratory microcosm experiment.

A microcosm experiment was carried out to study the influence of cadmium and diesel, individually and in a mixture, on a free living nematode community of a Tunisian lagoon. Sediments were contaminated with cadmium that ranged in concentration from 0.54 to 1.40 mg Cd kg(-1) (dry weight (dw)), by diesel at 0.25 mg kg(-1) (dw), by a cadmium-diesel mixture (Cd at 1.40 mg kg(-1)+Diesel at 0.25 mg kg(-1)) and effects were examined after 90 days. Univariate analysis showed that all univariate indices did not change significantly neither at all the levels of cadmium contamination nor at 0.25 mg kg(-1) (dw) diesel concentration. But, at the cadmium-diesel mixture, significant differences were recorded between nematode assemblages from uncontaminated sediment control microcosm and those from cadmium-diesel mixture amended sediment treatments. Total nematode abundance (I), mean individual weight (bi), Shannon-Weaver index H', species richness (d), evenness (J') and number of species (S) decreased significantly in microcosms contaminated with both cadmium and diesel. Results from multivariate analyses of the species abundance data demonstrated that responses of nematode species to the cadmium-diesel treatments were varied: Marylynnia stekhoveni, Calomicrolaimus honestus and Oncholaimellus mediterraneus were significantly affected at the cadmium-diesel contamination but they were not eliminated. These species could be categorized as "cadmium-diesel sensitive". Enoploides sp. and Oncholaimus campylocercoides, characterized by increased abundances in cadmium-diesel amended sediment, seemed to be "cadmium-diesel resistant" species. All these species, "cadmium-diesel sensitive" or "cadmium-diesel resistant", were not affected by either cadmium or diesel alone.